Patent Application
20250174724
Embodiments of the subject matter disclosed herein relate to electrolytes for secondary batteries, such as secondary batteries including a multivalent metal electrode, and more particularly to liquid electrolytes for use in such secondary batteries and methods for making the liquid electrolytes.
The current market for rechargeable, or secondary, batteries is dominated by lithium-ion batteries (LIBs). LIBs have been developed for several decades to achieve acceptable energy densities, cycle life, and rate performance, driven by factors such as decarbonization. However, the uneven distribution of raw materials used to manufacture LIBs, such as cobalt, has increased concerns of supply chain reliability. Rechargeable batteries that rely on alternative materials, such as other alkali-ion batteries, e.g., sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs), as well as multivalent batteries (MIBs) (that is, secondary batteries that rely upon multivalent metal ions), such as magnesium batteries, zinc batteries, and aluminum batteries (AIBs), have been developed to provide other options. For SIBs and PIBs, the relatively high reactivity of sodium and potassium can present challenges to battery stability in various examples. For MIBs, one issue in some examples can be the relatively high cost and corrosivity of liquid electrolytes used for ion transfer. The corrosion of the cell case caused by such liquid electrolytes in various examples can result in more expensive and/or lower performance endeavors, such as the use of specially designed high corrosion-resistant cell cases, a man-made (e.g., artificially imposed) voltage limit and cycle life limit, and an extra protection module added to the battery pack.
Techniques described and suggested herein include at least one embodiment of an electrolyte composition, including: solvent; and a salt including Al(TFSI)3 at least partially dissolved in the solvent at a concentration of 0.3 M to 1 M, wherein the electrolyte composition may be free of chlorine ions.
In at least one embodiment, a method for forming an electrolyte composition may include: performing a surface treatment of Al foil; performing a neutralization reaction of the surface-treated Al foil with a Lewis acid at a temperature between 90° C. and 100° C. to generate a product powder; dehydrating the product powder to obtain an electrolyte salt; and dissolving the electrolyte salt in a solvent until a solution having a target concentration of the electrolyte salt is formed, wherein the target concentration of the electrolyte salt may be between 0.3 M and 1 M and wherein the solution may be free of chlorine ions.
In at least one embodiment, an aluminum-based secondary battery system may include: a cell stack, including: a stainless steel cathode; an Al foil anode; a separator interposed between the stainless steel cathode and the Al foil anode; and an electrolyte composition fluidly coupling the stainless steel cathode and the Al foil anode across the separator, the electrolyte composition including: a solvent; and an Al salt at least partially dissolved in the solvent at a concentration of 0.3 M to 1 M, wherein the electrolyte composition may be free of chlorine; and a casing enclosing the cell stack.
These, as well as other aspects, advantages, and alternatives will become apparent to those of ordinary skill in the art by reading the following detailed description, with reference where appropriate to the accompanying drawings. Further, it should be understood that descriptions and figures provided herein are intended to illustrate the invention by way of example only and, as such, that numerous variations are possible.
For example, the following description relates to various embodiments of non-corrosive liquid electrolytes for MIBs and methods to synthesize or otherwise make non-corrosive liquid electrolytes that eliminate the chlorine element. The non-corrosive liquid electrolytes illustrated in the present disclosure significantly improve corrosion resistance as well as reduce subsequent cell production cost.
MIBs of various embodiments can use corrosive liquid electrolytes for ion migration between electrodes in such electrolytes. For example, AIBs can use an ionic liquid (IL) having aluminum chloride (AlCl3) and 1-ethyl-3-methylimidazolium chloride (EMIMCl) as a liquid electrolyte. The advantages of IL in various examples can include a wide electrochemical window of up to 2.2 V and acceptable ionic conductivity. However, ILs in some examples suffer from high material costs, low production efficiency, and strict environmental control during production. In certain examples, preparation of ILs can be an exothermic mixing process. In addition, various ILs may contain halogens, such as chlorine. Thus, the prepared ILs can be extremely hydrophilic in some examples. In certain examples, the hydrolyzed products can be corrosive vapors, such as HCl. During storage or application of ILs, in various embodiments packaging of a container and a cell can provide a water-free environment to isolate the ILs from ambient air. One or more of these drawbacks can increase the manufacturing, storage, transportation, and application costs of IL in some embodiments. For example, the highly corrosive electrolytes using ILs can easily corrode in some examples through commonly seen cell cases made of 304 stainless steel (SS), 316 SS, and Al-coated SS. Therefore, expensive materials like molybdenum, gold, and platinum can be used to coat the inner surface of the cell case to increase the corrosion resistance. However, the cost and/or availability of raw materials can prohibit the scaling-up of manufacturing cell cases using such expensive materials.
In this disclosure, a new technical approach to making non-corrosive liquid electrolytes for MIBs is demonstrated, which can be desirable in various embodiments. The disclosed non-corrosive liquid electrolytes in some embodiments can have a wide electrochemical window, a high ionic conductivity, and a good compatibility with SS even at 2 V. Although the present disclosure uses AIBs as an example to demonstrate the capabilities of some embodiments of non-corrosive liquid electrolytes and the applicability of the technical approach to make some embodiments of non-corrosive liquid electrolytes, in various examples the disclosed non-corrosive liquid electrolytes and the technical approach can also be applied to other MIBs, such as magnesium batteries and zinc batteries.
In at least one embodiment, the process 100 may include preparing one or more reactants at least by performing 102 surface treatment of an Al foil (or other metal foil) and cutting and cleaning 104 the treated Al foil. In certain examples, the surface treatment may include mechanical polishing and/or chemical etching. In certain examples, the surface treatment may reduce an amount of surface oxides and/or increase a surface area of the Al foil.
In at least one embodiment, the process 100 may include reacting the one or more reactants at least by weighing and mixing 106 the Al foil (e.g., as surface treated and cut and cleaned) and a Lewis acid into a reactor and performing 108 a reaction therebetween (e.g., a neutralization reaction between the Lewis acid and a Lewis base such as the Al foil, aluminum oxide powders, and/or any other aluminum species or compounds) at an elevated temperature (e.g., 90° C. to 100° C.) to generate a target product powder (e.g., the electrolyte salt).
In at least one embodiment, the process 100 may include purifying and collecting the target product powder at least by separating 110 the target product powder from at least a portion of any unreacted raw materials, performing 112 a first stage of dehydration of the target product powder, performing 114 a second stage of dehydration of the target product powder, and separating 116 the target product powder from any unreacted raw materials that may remain following dehydration. In certain examples, the dehydration may be performed immediately after salt preparation (e.g., before further steps).
In some examples, the target product powder may include a salt usable in an electrolytic composition for an Al-based secondary battery system, such as an Al salt. In certain examples, the salt may include Al(TFSI)3, Al(FSI)3, AlI3, and/or any other aluminum salts that can be used in AIBs. In additional or alternative examples, analogues can be substituted in the salt, depending on a transferring ion used in a given MIB.
Process 200 can be applied in some embodiments to prepare solvents including one or more carbonates, ethers, sulfonates, and/or any other suitable solvents that can dissolve the salts synthesized by the process 100 of
In at least one embodiment, the salt, e.g., as prepared via the process 100 of
In at least one embodiment, the process 300 may include drying and placing 302 a container into an inert atmosphere. In at least one embodiment, the process 300 may include weighing and adding 304 one or more salts and one or more solvents into the container.
In at least one embodiment, the process 300 may include determining or otherwise inferring 306 whether or not the one or more salts are fully dissolvable in the one or more solvents, that is, to yield a solution having a target concentration (e.g., of the one or more salts). In at least one embodiment, if it is determined or otherwise inferred 306 that the one or more salts are not fully dissolvable in the one or more solvents, the process 300 may include obtaining 308 one or more new solvents, and the one or more salts and the one or more new solvents may be weighed and added 304 into a new container (e.g., that has been dried and placed into an inert atmosphere).
In at least one embodiment, if it is determined or otherwise inferred 306 the one or more salts are fully dissolvable in the one or more solvents, the process 300 may include adding 310 one or more additives into the solution (e.g., having the target concentration). In at least one embodiment, the process 300 may include determining or otherwise inferring 312 whether or not the one or more additives are fully dissolvable (e.g., to yield a solution having a target concentration of the one or more additives). In at least one embodiment, if it is determined or otherwise inferred 312 that the one or more additives are not fully dissolvable in the one or more solvents, one or more new solvents may be obtained 308 and the one or more additives may be (re)added 310 into the solution (e.g., after the one or more salts and the one or more new solvents are weighed and added 304 into a container that has been dried and placed into an inert atmosphere).
In at least one embodiment, if it is determined or otherwise inferred 312 that the one or more additives are fully dissolvable in the one or more solvents, the process 300 may include checking and ensuring 314 that the one or more salts and the one or more additives are fully dissolved (e.g., through additional stirring, addition of heat, etc.). In at least one embodiment, the process 300 may include purifying 316 the solution (e.g., including the one or more salts and the one or more additives) to remove any impurities. In at least one embodiment, the process 300 may include retrieving 318 the solution for testing.
In some examples, the resultant solution may be an electrolytic composition usable in an Al-based secondary battery system. In certain examples, the electrolytic composition may be free of chlorine ions. In certain examples, the electrolyte composition may be non-corrosive (e.g., less than a threshold level of corrosiveness) towards certain cell case materials (e.g., stainless steel).
In some examples, a concentration of a salt in the electrolytic composition may be in a range from 0 to the concentration of a saturated solution of the salt in a solvent used to form the electrolytic composition. In certain examples, the salt concentration may be in a range from 0 to 1 M. In certain examples, the salt concentration may be in a range from 0.3 M to 1 M.
In some examples, the electrolytic composition may include one or more additives, such as an inorganic species or an organic compound. In certain examples, the one or more additives may include a halide (e.g., AlI3 or AlBr3). In certain examples, the one or more additives may include crown.
In some examples, a concentration of the one or more additives in the electrolytic composition may be in a range from 5 wt % to 40 wt %. In certain examples, the additive concentration may be in a range from 5 wt % to 30 wt %. In certain examples, the additive concentration may be in a range from 10 wt % to 20 wt %.
In some examples, an ionic conductivity of the electrolytic composition may be in a range of 1×10−5 S/cm-1×10−2 S/cm. In certain examples, the ionic conductivity may be in a range of 1×10−3 S/cm-1×10−2 S/cm. In certain examples, the ionic conductivity may be in a range of 2.9×10−3 S/cm-6.9×10−3 S/cm.
One factor influencing the electrolyte performance may include the solubility of salt in a solvent. Table 2 presents the highest concentration of Al(TFSI)3 achieved in representative solvents in various experiments. In Table 2, the numbers in parentheses indicates the concentration of additive with respect to the mass of Al(TFSI)3. For example, a unit cell coordinated to NaCl and DME displays 0.3 M (30 wt %) meaning, during the experiments, the highest concentration of Al(TFSI)3 prepared was 0.3 M with 30 wt % NaCl (with respect to the mass of Al(TFSI)3) as an additive in a solvent of DME. The concentrations listed in Table 2 are for illustrative purposes, and may or may not be the concentrations of saturated solutions of respective salt-additive-solvent systems and methods of various embodiments. For example, it is contemplated that the concentration of a saturated solution of Al(TFSI)3 in DME can be above 1 M. However, in the experiments, the highest concentration of Al(TFSI)3 in DME solution prepared was 1 M.
The example electrolyte preparation methods shown in
The impurities in various embodiments can include unreacted materials and water, which may be removed by a filtration and dehydration process. An accompanied heat release during the synthetic process in various examples may be negligible compared to that undergone during the preparation processes of various ILs. The existence of water in the salt, solvent, additive, and/or electrolyte in various embodiments may: increase the impurity level in the salt, solvent, additive, and/or electrolyte; hydrolyze the salt, solvent, and/or electrolyte; and/or introduce side reactions during battery cycling in some examples. The surface treatment in the process 100 of
It is noted that the salts and solvents illustrated in
When implementing the disclosed technology, the liquid electrolytes were tested in various testing devices such as coin cells using SS as a cathode and Al foil as an anode. One such coin cell 400 is illustrated in
Example representative liquid electrolytes tested are presented in Table 3.
The present disclosure will describe the implementation of example embodiments of the disclosed technology based on each representative category of solvents.
Ethers can be used for liquid electrolytes in rechargeable batteries. When implementing such ethers as solvents for liquid electrolytes in MIBs, the preparation process can follow the procedures described in
In some embodiments, 0.3 M Al(TFSI)3 in various ether-based solvents can be used as liquid electrolytes. As shown in
In some embodiments, one or more additives can be added into ether-based electrolytes, referring to the example experiment of
As shown in the example experiment of
To explore the origin of the enhanced performance of 0.3 M Al(TFSI)3 and 20 wt % AlBr3 in DME, AlBr3 was replaced with NaBr while keeping the concentration of Br−, as shown in
In some experiments, Al2O3 was investigated to explore the feasibility of replacing Al foil in the method of
In some embodiments, the existence of aluminum cation in the additives is demonstrated to be desirable. To better understand the function of anions in the additives, halides were added as additives in example experiments. As shown in the example experiments of
In some embodiments, ethylal can be used as a linear ether solvent to make electrolytes of 0.3 M Al(TFSI)3 in ethylal with different additives, as shown in the example experiment of
When another linear ether, DEGDME, was used as the electrolyte solvent, adding AlBr3 as an additive (A51_11) also shows significant electrolyte oxidation, SS corrosion, or both electrolyte oxidation and SS corrosion when voltage is >1.0 V (A51_11 in the example experiment of
As shown in the example experiment of
As shown in the example experiment of
For cyclic ethers, THF can be used as an example representative electrolyte solvent. As shown in the example experiment of
Referring to the example experiment of
In some embodiments, a mixture including linear ethers and cyclic ethers can be used as an electrolyte solvent. As shown in the example experiment of
Electrolytes for MIBs can include Cl-free salts and Cl-free solvents. In some embodiments, the electrolytes may further include one or more additives. During implementation in AIBs, one representative Cl-free salt can be Al(TFSI)3. One example representative Cl-free solvent can include an ether or a combination of multiple ethers. The ether in some embodiments can be a linear ether, a cyclic ether, a mixture of a linear ether and a cyclic ether, etc. The Cl-free salt concentration in some embodiments can be in a range from 0 to the concentration of a saturated solution. In additional or alternative examples, the Cl-free salt concentration can be in a range from 0 to 1 M. In additional or alternative examples, the Cl-free salt concentration can be in a range from 0.3 M to 1 M. In some embodiments, Al(TFSI)3 may have lower solubility in some solvents. The concentration mentioned above, e.g., 0.3 M and 1 M, shall not be higher than the Al(TFSI)3 concentration of a saturated solution in some embodiments. In some embodiments, the one or more additives include inorganic species, such as halides, and/or organic compounds, such as crown. Additive concentration can be in a range from 5 wt % to 40 wt % in some examples. In additional or alternative examples, the additive concentration can be in a range from 5 wt % to 30 wt %. In additional or alternative examples, the additive concentration can be in a range from 10 wt % to 20 wt %. In some embodiments, the starting materials to synthesize Al(TFSI)3 can either be Al foil or Al2O3 depending on factors like production cost, purification requirements, and/or accessible equipment. Some example representative electrolytes, like 0.25 M Al(TFSI)3+5 wt % NaCl in DME, 0.3 M Al(TFSI)3+20 wt % AlBr3 in DME, and 0.3 M Al(TFSI)3+20 wt % crown in DME, can have reversible aluminum plating/stripping demonstrated by symmetrical peaks in a range of −1 V to −0.5 V and in a range of 0.5 V to 1.5 V, respectively. Electrolyte oxidation, SS corrosion, or both electrolyte oxidation and SS corrosion did not happen in some example experiments until the voltage was ˜2 V in the representative electrolytes.
In some example experiments, carbonates were tested as electrolyte solvents for MIBs.
In some embodiments, when noisy signals appear, a resting step may be performed to passivate the electrode surface. As shown in the example experiment of
Adding additives to the linear carbonate-based electrolytes can improve aluminum plating and stripping in some embodiments. As shown in the example experiment of
As shown in the example experiment of
In some embodiments, AlI3 can be added into 0.5 M Al(TFSI)3 in DMC as an additive, as shown in the example experiment of
In some embodiments, a linear carbonate can be mixed with a cyclic carbonate to be used as an electrolyte solvent. As shown in the example experiment of
In some embodiments, one or more additives can be added into the Al(TFSI)3 in FEC/DEC, as shown in the example experiment of
Electrolytes for MIBs can include Cl-free salts and Cl-free solvents. In some embodiments, the electrolytes further include one or more additives. During implementation in AIBs, one example representative Cl-free salt can be Al(TFSI)3. One example representative Cl-free solvent can include a carbonate or a combination of multiple carbonates. The carbonate in some embodiments can be a linear carbonate, a cyclic carbonate, a mixture of linear carbonate and cyclic carbonate, etc. The Cl-free salt concentration in some examples can be in a range from 0 to the concentration of a saturated solution. In additional or alternative examples, the Cl-free salt concentration can be in a range from 0 to 1 M. In additional or alternative examples, the Cl-free salt concentration can be in a range from 0.3 M to 1 M. In some embodiments, Al(TFSI)3 may have lower solubility in some solvents. The concentration in some embodiments, e.g., 0.3 M and 1 M, shall not be higher than the Al(TFSI)3 concentration of a saturated solution. In some embodiments, the one or more additives can include inorganic species, such as halides, and/or organic compounds, such as crown. Additive concentration in some examples can be in a range from 5 wt % to 40 wt %. In additional or alternative examples, the additive concentration can be in a range from 5 wt % to 30 wt %. In additional or alternative examples, the additive concentration can be in a range from 10 wt % to 20 wt %. In some embodiments, the starting materials to synthesize Al(TFSI)3 can either be Al foil or Al2O3 depending on the factors like production cost, purification requirements, and/or accessible equipment. When noisy signals appear, a 24-hour resting step may be performed in some embodiments to passivate the electrode surface prior to cycling. In some embodiments, the 24-hour resting step can be applied in cell testing as a preventive measure, even for the electrolytes that do not deliver noisy signals. Some example representative electrolytes, like 0.3 M Al(TFSI)3+20 wt % AlBr3 in FEC(5 vol %)/DEC, 0.3 M Al(TFSI)3+20 wt % crown in FEC(5 vol %)/DEC, and 0.3 M Al(TFSI)3+20 wt % AlBr3 in FEC(10 vol %)/DEC, can have reversible aluminum plating/stripping demonstrated by symmetrical peaks in a range of −1 V to −0.5 V and in a range of 0.5 V to 1.5 V, respectively. Electrolyte oxidation, SS corrosion, or both electrolyte oxidation and SS corrosion did not happen until the voltage is ˜2 V in the representative electrolytes in some example experiments.
In some embodiments, acetates are used as electrolyte solvents. For example, when EA was used, as shown in the example experiment of
Electrolytes for MIBs can include Cl-free salts and Cl-free solvents. In some embodiments, the electrolytes further include one or more additives. During implementation in AIBs, in some embodiments one example representative Cl-free salt can be Al(TFSI)3. One example representative Cl-free solvent can include an acetate or a combination of multiple acetates. The Cl-free salt concentration in some examples can be in a range from 0 to the concentration of a saturated solution. In additional or alternative examples, the Cl-free salt concentration can be in a range from 0 to 1 M. In additional or alternative examples, the Cl-free salt concentration can be in a range from 0.3 M to 1 M. In some embodiments, Al(TFSI)3 has lower solubility in some solvents. The concentration of certain embodiments, e.g., 0.3 M and 1 M, shall not be higher than the Al(TFSI)3 concentration of the saturated solution. In some embodiments, the one or more additives can include inorganic species, such as halides, and/or organic compounds, such as crown. Additive concentration in some examples can be in a range from 5 wt % to 40 wt %. In additional or alternative examples, the additive concentration can be in a range from 5 wt % to 30 wt %. In additional or alternative examples, the additive concentration can be in a range from 10 wt % to 20 wt %. Some example representative electrolytes, like 0.3 M Al(TFSI)3+20 wt % AlBr3 in EA, can have excellent reversible aluminum plating/stripping, which can be demonstrated in some experiments by symmetrical peaks in a range of −1 V to −0.5 V and in a range of 0.5 V to 1 V, respectively.
In some embodiments, organosulfurs are used as electrolyte solvents. For example, in the example experiment of
Referring to the example experiment of
Electrolytes for MIBs can include Cl-free salts and Cl-free solvents. In some embodiments, the electrolytes further include one or more additives. During implementation in AIBs in some embodiments, one example representative Cl-free salt can be Al(TFSI)3. One representative Cl-free solvent can include an organosulfur or a combination of multiple organosulfurs. The Cl-free salt concentration in some examples can be in a range from 0 to the concentration of a saturated solution. In additional or alternative examples, the Cl-free salt concentration can be in a range from 0 to 1 M. In additional or alternative examples, the Cl-free salt concentration can be in a range from 0.3 M to 1 M. In some embodiments, Al(TFSI)3 has lower solubility in some solvents. The concentration in some embodiments, e.g., 0.3 M and 1 M, shall not be higher than the Al(TFSI)3 concentration of a saturated solution. In some embodiments, the one or more additives can include inorganic species, such as halides, and/or organic compounds, such as crown. Additive concentration in some examples can be in a range from 5 wt % to 40 wt %. In additional or alternative examples, the additive concentration can be in a range from 5 wt % to 30 wt %. In additional or alternative examples, the additive concentration can be in a range from 10 wt % to 20 wt %. When noisy signals appear, in some examples it may be desirable to include a 24-hour resting step to passivate the electrode surface prior to cycling. In some embodiments, the 24-hour resting step can be applied in cell testing as a preventive measure, even for the electrolytes that do not deliver noisy signals. Some example representative electrolytes, like 0.3 M Al(TFSI)3+20 wt % AlBr3 in DMSO, can have reversible aluminum plating/stripping demonstrated by symmetrical peaks in a range of −1 V to −0.5 V and in a range of 0.5 V to 1 V, respectively, in some experiments.
In some embodiments, amides are used as electrolyte solvents. For example, when DMF was used, as shown in the example experiment of
Electrolytes for MIBs can include Cl-free salts and Cl-free solvents. In some embodiments, the electrolytes can further include one or more additives. During implementation in AIBs in some embodiments, one example representative Cl-free salt can be Al(TFSI)3. One example representative Cl-free solvent can include an amide or a combination of multiple amides. The Cl-free salt concentration in some examples can be in a range from 0 to the concentration of a saturated solution. In additional or alternative examples, the Cl-free salt concentration can be in a range from 0 to 1 M. In additional or alternative examples, the Cl-free salt concentration can be in a range from 0.3 M to 1 M. In some embodiments, Al(TFSI)3 may have lower solubility in some solvents. The concentration in some embodiments, e.g., 0.3 M and 1 M, shall not be higher than the Al(TFSI)3 concentration of a saturated solution. In some embodiments, the one or more additives can include inorganic species, such as halides, and/or organic compounds, such as crown. Additive concentration in some examples can be in a range from 5 wt % to 40 wt %. In additional or alternative examples, the additive concentration can be in a range from 5 wt % to 30 wt %. In additional or alternative examples, the additive concentration can be in a range from 10 wt % to 20 wt %. In some embodiments, the starting materials to synthesize Al(TFSI)3 can either be Al foil or Al2O3 depending on factors like production cost, purification requirements, and/or accessible equipment. Some example representative electrolytes, like 0.3 M Al(TFSI)3+20 wt % AlBr3 in DMF, can show reversible aluminum plating/stripping behaviors in some embodiments, which may be demonstrated in some examples by symmetrical peaks in a range of −1 V to −0.5 V and in a range of 0.5 V to 1 V, respectively.
In some embodiments, nitriles can be used as electrolyte solvents. For example, when ACN is used in some embodiments, such as shown in the example experiment of
Electrolytes for MIBs can include Cl-free salts and Cl-free solvents. In some embodiments, the electrolytes further include one or more additives. During implementation in AIBs in some embodiments, one example representative Cl-free salt can be Al(TFSI)3. One example representative Cl-free solvent can include a nitrile or a combination of multiple nitriles. The Cl-free salt concentration in some examples can be in a range from 0 to the concentration of a saturated solution. In additional or alternative examples, the Cl-free salt concentration can be in a range from 0 to 1 M. In additional or alternative examples, the Cl-free salt concentration can be in a range from 0.3 M to 1 M. In some embodiments, the one or more additives can include inorganic species, such as halides, and/or organic compounds, such as crown. Additive concentration in some examples can be in a range from 5 wt % to 40 wt %. In additional or alternative examples, the additive concentration can be in a range from 5 wt % to 30 wt %. In additional or alternative examples, the additive concentration can be in a range from 10 wt % to 20 wt %. In some embodiments, the starting materials to synthesize Al(TFSI)3 can either be Al foil or Al2O3 depending on factors like production cost, purification requirements, and/or accessible equipment. Some example representative electrolytes, like 0.3 M Al(TFSI)3+20 wt % AlBr3 in ACN, can have acceptable aluminum plating/stripping demonstrated by peaks in a range of −1 V to −0.5 V or ˜1.5 V, respectively, in some example experiments.
In some embodiments, pyrrolidones are used as electrolyte solvents. For example, in some examples when NMP is used, such as shown in the example experiment of
Electrolytes for MIBs can include Cl-free salts and Cl-free solvents. In some embodiments, the electrolytes further include one or more additives. During implementation in AIBs in some embodiments, one example representative Cl-free salt can be Al(TFSI)3. One example representative Cl-free solvent can include a pyrrolidone or a combination of multiple pyrrolidones. The Cl-free salt concentration in some examples can be in a range from 0 to the concentration of a saturated solution. In additional or alternative examples, the Cl-free salt concentration can be in a range from 0 to 1 M. In additional or alternative examples, the Cl-free salt concentration can be in a range from 0.3 M to 1 M. In some embodiments, the one or more additives can include inorganic species, such as halides, and/or organic compounds, such as crown. Additive concentration in some examples can be in a range from 5 wt % to 40 wt %. In additional or alternative examples, the additive concentration can be in a range from 5 wt % to 30 wt %. In additional or alternative examples, the additive concentration can be in a range from 10 wt % to 20 wt %. Some representative electrolytes, like 0.3 M Al(TFSI)3+20 wt % AlBr3 in NMP, can have acceptable aluminum plating/stripping in some embodiments, which can be demonstrated by peaks in a voltage range of −1 V to −0.5 V and in a voltage range of 1 V to 1.5 V, respectively, in some example experiments.
In some embodiments, pyridine can be used as the electrolyte solvent. As shown in the example experiment of
In some embodiments, the relatively high reactivity of pyridine and the relatively low solubility of Al(TFSI)3 in pyridine may result in noisy signals. Thus, a 24-hour resting step can be added (K11r and K11_21or) prior to cycling to minimize the noisy signals. In K11_21or, Al2O3 was used to synthesize Al(TFSI)3 instead of Al foil to demonstrate alternative synthesis pathways in this example.
Electrolytes for MIBs can include Cl-free salts and Cl-free solvents. In some embodiments, the electrolytes further include one or more additives. During implementation in AIBs in some embodiments, one example representative Cl-free salt can be Al(TFSI)3. One example representative Cl-free solvent can include a pyridine or a combination of multiple pyridines. The Cl-free salt concentration in some examples can be in a range from 0 to the concentration of a saturated solution. In additional or alternative examples, the Cl-free salt concentration can be in a range from 0 to 1 M. In additional or alternative examples, the Cl-free salt concentration can be in a range from 0.3 M to 1 M. In some embodiments, Al(TFSI)3 has lower solubility in some solvents. The concentration, e.g., 0.3 M and 1 M in some embodiments, shall not be higher than the concentration of a saturated solution of Al(TFSI)3 in a corresponding solvent. In some embodiments, the one or more additives can include inorganic species, such as halides, and/or organic compounds, such as crown. Additive concentration in some examples can be in a range from 5 wt % to 40 wt %. In additional or alternative examples, the additive concentration can be in a range from 5 wt % to 30 wt %. In additional or alternative examples, the additive concentration can be in a range from 10 wt % to 20 wt %. In some embodiments, the starting materials to synthesize Al(TFSI)3 can either be Al foil or Al2O3 depending on factors like production cost, purification requirements, and/or accessible equipment. When noisy signals appear, it may be desirable to include a 24-hour resting step to passivate the electrode surface prior to cycling. In some embodiments, such a 24-hour resting step can be applied in cell testing as a preventive measure, even for the electrolytes that do not deliver noisy signals.
Electrolyte Salts Other than Al(TFSI)3
In some embodiments, when implementing the synthetic methods presented in
In some embodiments, AlI3 in DMSO can be used as an electrolyte. As shown in the example experiment of
Electrolytes for MIBs can include Cl-free salts and Cl-free solvents. In some embodiments, the electrolytes may further include one or more additives. During implementation in AIBs in some embodiments, one example representative Cl-free salt can be AlI3. One example representative Cl-free solvent can include DMC or DMSO. The Cl-free salt concentration in some examples can be in a range from 0 to the concentration of a saturated solution. In additional or alternative examples, the Cl-free salt concentration can be in a range from 0 to 1 M. In additional or alternative examples, the Cl-free salt concentration can be in a range from 0.3 M to 0.5 M. In some embodiments, AlI3 has lower solubility in some solvents. The concentration, e.g., 0.3 M and 1 M, shall not be higher than the concentration of saturated solution of AlI3 in a corresponding solvent in some embodiments. When noisy signals appear, in some embodiments it may be desirable to include a 24-hour resting step to passivate the electrode surface prior to cycling. In some embodiments, the 24-hour resting step can be applied in cell testing as a preventive measure, even for the electrolytes that do not deliver noisy signals. Some example representative electrolytes, like 0.5 M AlI3 in DMC and 0.5 M AlI3 in DMSO, can have acceptable aluminum plating/stripping in some embodiments, which can be demonstrated by a wave at a voltage of ˜−0.5 V and in a voltage range of 1 V to 1.7 V, respectively, in some example experiments.
In some embodiments, the liquid electrolytes display an ionic conductivity in a range of 1×10−5-1×10−2 S/cm. In additional or alternative embodiments, the ionic conductivity can be in a range of 1×10−3-1×10−2 S/cm. As shown in the example experiments of
L is the thickness of the separator, as illustrated in the example experiment of
The specification and drawings are to be regarded in an illustrative rather than a restrictive sense. It will, however, be evident that various modifications and changes may be made thereunto without departing from the broader spirit and scope of the invention as set forth in the claims. That is, the described embodiments are susceptible to various modifications and alternative forms, and specific examples thereof have been shown by way of example in the drawings and are herein described in detail.
Other variations are within the spirit of the present disclosure. Thus, while the disclosed techniques are susceptible to various modifications and alternative constructions, certain illustrated embodiments thereof are shown in the drawings and have been described above in detail. It should be understood, however, that there is no intention to limit the invention to the specific form or forms disclosed but, on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention, as defined in the appended claims. Additionally, elements of a given embodiment should not be construed to be applicable to only that example embodiment and therefore elements of one example embodiment can be applicable to other embodiments. Additionally, in some embodiments, elements that are specifically shown in some embodiments can be explicitly absent from further embodiments. Accordingly, the recitation of an element being present in one example should be construed to support some embodiments where such an element is explicitly absent.
The use of the terms “a” and “an” and “the” and similar referents in the context of describing the disclosed embodiments (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Similarly, use of the term “or” is to be construed to mean “and/or” unless contradicted explicitly or by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. The term “connected,” when unmodified and referring to physical connections, is to be construed as partly or wholly contained within, attached to, or joined together, even if there is something intervening. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. The use of the term “set” (e.g., “a set of items”) or “subset” unless otherwise noted or contradicted by context, is to be construed as a nonempty collection comprising one or more members. Further, unless otherwise noted or contradicted by context, the term “subset” of a corresponding set does not necessarily denote a proper subset of the corresponding set, but the subset and the corresponding set may be equal. The use of the phrase “based on,” unless otherwise explicitly stated or clear from context, means “based at least in part on” and is not limited to “based solely on.”
Conjunctive language, such as phrases of the form “at least one of A, B, and C,” or “at least one of A, B and C,” (i.e., the same phrase with or without the Oxford comma) unless specifically stated otherwise or otherwise clearly contradicted by context, is otherwise understood within the context as used in general to present that an item, term, etc., may be either A or B or C, any nonempty subset of the set of A and B and C, or any set not contradicted by context or otherwise excluded that contains at least one A, at least one B, or at least one C. For instance, in the illustrative example of a set having three members, the conjunctive phrases “at least one of A, B, and C” and “at least one of A, B and C” refer to any of the following sets: {A}, {B}, {C}, {A, B}, {A, C}, {B, C}, {A, B, C}, and, if not contradicted explicitly or by context, any set having {A}, {B}, and/or {C} as a subset (e.g., sets with multiple “A”). Thus, such conjunctive language is not generally intended to imply that certain embodiments require at least one of A, at least one of B and at least one of C each to be present. Similarly, phrases such as “at least one of A, B, or C” and “at least one of A, B or C” refer to the same as “at least one of A, B, and C” and “at least one of A, B and C” refer to any of the following sets: {A}, {B}, {C}, {A, B}, {A, C}, {B, C}, {A, B, C}, unless differing meaning is explicitly stated or clear from context. In addition, unless otherwise noted or contradicted by context, the term “plurality” indicates a state of being plural (e.g., “a plurality of items” indicates multiple items). The number of items in a plurality is at least two but can be more when so indicated either explicitly or by context.
Operations of processes described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. In an embodiment, a process such as those processes described herein (or variations and/or combinations thereof) is performed under the control of one or more computer systems configured with executable instructions and is implemented as code (e.g., executable instructions, one or more computer programs or one or more applications) executing collectively on one or more processors, by hardware or combinations thereof. In an embodiment, the code is stored on a computer-readable storage medium, for example, in the form of a computer program comprising a plurality of instructions executable by one or more processors. In an embodiment, a computer-readable storage medium is a non-transitory computer-readable storage medium that excludes transitory signals (e.g., a propagating transient electric or electromagnetic transmission) but includes non-transitory data storage circuitry (e.g., buffers, cache, and queues) within transceivers of transitory signals. In an embodiment, code (e.g., executable code or source code) is stored on a set of one or more non-transitory computer-readable storage media having stored thereon executable instructions that, when executed (i.e., as a result of being executed) by one or more processors of a computer system, cause the computer system to perform operations described herein. The set of non-transitory computer-readable storage media, in an embodiment, comprises multiple non-transitory computer-readable storage media, and one or more of individual non-transitory storage media of the multiple non-transitory computer-readable storage media lack all of the code while the multiple non-transitory computer-readable storage media collectively store all of the code. In an embodiment, the executable instructions are executed such that different instructions are executed by different processors for example, in an embodiment, a non-transitory computer-readable storage medium stores instructions and a main CPU executes some of the instructions while a graphics processor unit executes other instructions. In another embodiment, different components of a computer system have separate processors and different processors execute different subsets of the instructions.
Accordingly, in an embodiment, computer systems are configured to implement one or more services that singly or collectively perform operations of processes described herein, and such computer systems are configured with applicable hardware and/or software that enable the performance of the operations. Further, a computer system, in an embodiment of the present disclosure, is a single device and, in another embodiment, is a distributed computer system comprising multiple devices that operate differently such that the distributed computer system performs the operations described herein and such that a single device does not perform all operations.
Embodiments of the present disclosure can be described in view of the following clauses:
1. An electrolyte composition, comprising:
2. The electrolyte composition of clause 1, further comprising:
3. The electrolyte composition of clause 2, wherein the one or more additives comprise a halide.
4. The electrolyte composition of clause 3, wherein the halide comprises AlBr3 or AlI3.
5. The electrolyte composition of any one of clauses 2-4, wherein the one or more additives comprise crown.
6. The electrolyte composition of any one of clauses 1-5, wherein the solvent comprises an ether, a carbonate, an acetate, an organosulfur, an amide, a nitrile, a pyrrolidone, or a pyridine.
7. The electrolyte composition of any one of clauses 1-6, wherein an ionic conductivity of the electrolyte composition is in a range of 1×10−3 S/cm to 1×10−2 S/cm.
8. A method for forming an electrolyte composition, the method comprising:
9. The method of clause 8, further comprising:
10. The method of clause 9, wherein the one or more additives comprise a halide.
11. The method of any one of clauses 9 or 10, wherein the one or more additives comprise crown.
12. The method of any one of clauses 8-11, wherein the surface treatment comprises mechanical polishing and/or chemical etching.
13. The method of any one of clauses 8-12, wherein the surface treatment reduces an amount of surface oxides on the Al foil and increases a surface area of the Al foil.
14. The method of any one of clauses 8-13, wherein the electrolyte salt comprises Al(TFSI)3.
15. The method of any one of clauses 8-14, wherein the electrolyte salt comprises AlI3.
16. The method of any one of clauses 8-15, wherein the solvent comprises an ether, a carbonate, an acetate, an organosulfur, an amide, a nitrile, a pyrrolidone, or a pyridine.
17. An aluminum-based secondary battery system, comprising:
18. The aluminum-based secondary battery system of clause 17, wherein the Al salt comprises AlI3, Al(FSI)3, or Al(TFSI)3.
19. The aluminum-based secondary battery system of any one of clauses 17 or 18, wherein the solvent comprises an ether, a carbonate, an acetate, an organosulfur, an amide, a nitrile, a pyrrolidone, or a pyridine.
20. The aluminum-based secondary battery system of any one of clauses 17-19, wherein the electrolyte composition further comprises one or more additives at least partially dissolved in the solvent at a concentration of 5 wt % to 30 wt %, the one or more additives comprising a halide or crown.
The use of any and all examples or exemplary language (e.g., “such as”) provided herein is intended merely to better illuminate embodiments of the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
Embodiments of this disclosure are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for embodiments of the present disclosure to be practiced otherwise than as specifically described herein. Accordingly, the scope of the present disclosure includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the scope of the present disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.
All references including publications, patent applications, and patents cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
The present application claims priority to U.S. Provisional Application No. 63/604,072, entitled “NON-CORROSIVE LIQUID ELECTROLYTE FOR RECHARGEABLE MULTIVALENT BATTERIES AND METHODS OF MAKING THE SAME” and filed on Nov. 29, 2023. The entire contents of the above-identified application are hereby incorporated by reference for all purposes.
| Number | Date | Country | |
|---|---|---|---|
| 63604072 | Nov 2023 | US |
