Patent Application
20250006935
The information provided in this section is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
The present disclosure relates to battery cells, and more particularly to anode electrodes including lithium silicon oxide for battery cells.
Electric vehicles (EVs) such as battery electric vehicles (BEVs), hybrid vehicles, and/or fuel cell vehicles include one or more electric machines and a battery system including one or more battery cells, modules and/or packs. A battery control module is used to control charging and/or discharging of the battery system during charging and/or driving. Manufacturers of EVs are pursuing increased power density to increase the range of the EVs.
An anode electrode comprises an anode current collector. An anode active material layer comprises anode active material comprising at least one of lithium silicon oxide, silicon oxide, lithium silicon oxide and graphite, and silicon oxide and graphite. The anode active material layer further comprises a binder comprising a mixture of styrene butadiene rubber (SBR), sodium carboxymethyl cellulose (NaCMC) and sodium polyacrylic acid (NaPAA), wherein SBR comprises greater than 60% wt of the binder.
In other features, the anode active material layer further comprises a conductive filler. The conductive filler comprises first particles having an aspect ratio less than 2 and second particles having an aspect ratio greater than 20. The first particles comprise 0.1% wt to 3% wt of the anode active material layer. The first particles comprise 0.2% wt to 1% wt of the anode active material layer.
In other features, the first particles are selected from a group consisting of carbon black (CB) and acetylene black. The second particles are selected from a group consisting of graphene nanoplatelets, carbon nanofibers, multi-wall carbon nanotubes, and single-wall carbon nanotubes. The second particles comprise 0.05% wt to 2% wt of the anode active material layer.
In other features, the anode active material comprises at least one of the lithium silicon oxide and the silicon oxide, and wherein the at least one of the lithium silicon oxide and the silicon oxide comprises greater than 18% wt of the anode active material layer. The anode active material comprises 83% wt to 97% wt of the anode active material layer. The anode active material comprises 93% wt to 96% wt of the anode active material layer.
In other features, the SBR comprises 1% wt to 6% wt of the anode active material layer. The SBR comprises 1.2% wt to 3% wt of the anode active material layer. The NaCMC comprises 0.2% wt to 2% wt of the anode active material layer. The NaCMC comprises 0.3% wt to 1% wt of the anode active material layer. The NaPAA comprises 0.2% wt to 4% wt of the anode active material layer.
A battery cell comprises C cathode electrodes, A of the anode electrode, S separators, and a battery cell enclosure, where C, A and S are integers greater than one. The C cathode electrodes, the A anode electrodes, and the S separators are arranged in a predetermined sequence in the battery cell enclosure.
An anode electrode comprises an anode current collector. An anode active material layer comprises anode active material comprises at least one of lithium silicon oxide, silicon oxide, lithium silicon oxide and graphite, and silicon oxide and graphite. The anode active material layer comprises a binder comprising a mixture of styrene butadiene rubber (SBR) and sodium carboxymethyl cellulose (NaCMC). SBR comprises greater than 60% wt of the binder. A conductive filler comprises first particles having an aspect ratio less than 2 and second particles having an aspect ratio greater than 20.
In other features, the first particles comprise 0.1% wt to 3% wt of the anode active material layer, the first particles are selected from a group consisting of carbon black (CB) and acetylene black, the second particles comprise 0.05% wt to 2% wt of the anode active material layer, and the second particles are selected from a group consisting of graphene nanoplatelets, carbon nanofibers, multi-wall carbon nanotubes, and single-wall carbon nanotubes.
In other features, the anode active material comprises 83% wt to 97% wt of the anode active material layer, the SBR comprises from 1% wt to 6% wt of the anode active material layer, and the NaCMC comprises 0.2% wt to 2% wt of the anode active material layer.
In other features, the anode active material comprises at least one of the lithium silicon oxide and the silicon oxide. The at least one of the lithium silicon oxide and the silicon oxide comprises greater than 18% wt of the anode active material layer.
Further areas of applicability of the present disclosure will become apparent from the detailed description, the claims, and the drawings. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.
The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:
In the drawings, reference numbers may be reused to identify similar and/or identical elements.
While battery cells and anode electrodes according to the present disclosure are described in the context of electric vehicles, the battery cells and anode electrodes can be used in stationary applications and/or in other types of applications.
Battery cells include anode electrodes, cathode electrodes, and separators arranged in a predetermined sequence in an enclosure. The anode electrodes include an anode current collector and an anode active material layer arranged on one or both sides of the anode current collector. The anode active material layer includes anode active material, one or more binders, and/or one or more conductive fillers. The cathode electrodes include a cathode current collector and a cathode active material layer arranged on one or both sides of the cathode current collector. The cathode active material layer includes cathode active material, one or more binders, one or more additives, and/or one or more conductive fillers. The separators are arranged between the anode electrodes and the cathode electrodes.
As will be described further below, the anode active material layer of the anode electrodes according to the present disclosure includes a combination of active material(s), binder(s), and conductive filler(s) that optimize the processability and mechanical and electrochemical properties of the anode electrodes. In some examples, the anode active material comprises lithium silicon oxide (LiSiOx), silicon oxide (SiOx), lithium silicon oxide and graphite, and/or silicon oxide and graphite. In some examples, the silicon oxide comprises silicon monoxide, silicon dioxide, or silicon oxides where x is between 1 and 2 stoichiometric ratio.
In some examples, the anode active material comprises 83% wt to 97% wt of the anode active material layer. In some examples, the anode active material comprises 93% wt to 96% wt of the anode active material layer. In some examples, the LiSiOx or the SiOx comprises at least 18% wt of the anode active material layer (when LiSiOx or the SiOx are used alone or are blended with graphite or other materials).
In the anode active material layers according to the present disclosure, the binder includes styrene butadiene rubber (SBR) and/or other binder materials. In some examples, the SBR comprises greater than 60% wt of the binder. In some examples, the SBR comprises 1% wt to 6% wt of the anode active material layer. In some examples, the SBR comprises 1.2% wt to 3% wt of the anode active material layer.
In some examples, the other binder materials comprise at least one of sodium carboxymethyl cellulose (NaCMC) and sodium polyacrylic acid (NaPAA) to improve mechanical and electrochemical performance of the battery cells. In some examples, the NaCMC comprises 0.2% wt to 2% wt of the anode active material layer. In some examples, the NaCMC comprises 0.3% wt to 1% wt of the anode active material layer. In some examples, the NaPAA comprises 0.2% wt to 4% wt of the anode active material layer. In some examples, the NaPAA comprises 0.2% wt to 2% wt of the anode active material layer.
In some examples, the anode active material and the binder are combined with one or more conductive filler(s). In some examples, the one or more conductive fillers include first particles and second particles. In some examples, the first particles include one or more materials selected from a group consisting of carbon black (CB) and/or acetylene black. In some examples, the second particles include one or more materials selected from a group consisting of graphene nanoplatelets, carbon nanofibers, multi-wall carbon nanotubes, and/or single-wall carbon nanotubes.
In some examples, the first particles have an aspect ratio less than 2 (e.g., ˜1) and the second particles have an aspect ratio greater than or equal to 20 (e.g., 30, 40, 60, etc.). In some examples, the first particles comprise 0.1% wt to 3% wt of the anode active material layer. In some examples, the first particles comprise 0.2% wt to 1% wt of the anode active material layer. In some examples, the second particles comprise 0.05% wt to 2% wt of the anode active material layer.
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Lower viscosity corresponds to higher carbon dispersion, which avoids carbon agglomeration. Due to the combination of hydrophobic and hydrophilic segments of carboxymethyl cellulose (CMC), CMC is a good dispersant in water for hydrophobic carbons. This effect is exaggerated at lower degrees of substitution (DS) where the polymer has more hydrophobic segments. In some examples, the DS of the NaCMC is less than or equal to 1.0. In some examples, the DS of the NaCMC is less than or equal to 0.8.
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The foregoing description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims. It should be understood that one or more steps within a method may be executed in different order (or concurrently) without altering the principles of the present disclosure. Further, although each of the embodiments is described above as having certain features, any one or more of those features described with respect to any embodiment of the disclosure can be implemented in and/or combined with features of any of the other embodiments, even if that combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and permutations of one or more embodiments with one another remain within the scope of this disclosure.
Spatial and functional relationships between elements (for example, between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including “connected,” “engaged,” “coupled,” “adjacent,” “next to,” “on top of,” “above,” “below,” and “disposed.” Unless explicitly described as being “direct,” when a relationship between first and second elements is described in the above disclosure, that relationship can be a direct relationship where no other intervening elements are present between the first and second elements, but can also be an indirect relationship where one or more intervening elements are present (either spatially or functionally) between the first and second elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.”
In the figures, the direction of an arrow, as indicated by the arrowhead, generally demonstrates the flow of information (such as data or instructions) that is of interest to the illustration. For example, when element A and element B exchange a variety of information but information transmitted from element A to element B is relevant to the illustration, the arrow may point from element A to element B. This unidirectional arrow does not imply that no other information is transmitted from element B to element A. Further, for information sent from element A to element B, element B may send requests for, or receipt acknowledgements of, the information to element A.
