Patent Application
20200136175
The subject matter herein generally relates to lithium-ion batteries, and more particularly, to a cylindrical lithium-ion battery.
Traffic on the roads brings pressure on the energy crisis and environmental pollution, thus it is urgent to develop and research efficient, clean and safe new energy vehicles to achieve energy conservation and emission reduction. Lithium-ion batteries have become the best candidates for power systems of the new energy vehicles because of high specific energy, no pollution, and no memory effect. However, the lithium-ion batteries are very sensitive to temperature, and efficient discharge and good performance of the battery pack can be only obtained within a suitable temperature range. Operating at an elevated temperature may cause the lithium-ion battery to age faster and increase its thermal resistances faster. Furthermore, the cycling time becomes less, the service life becomes shorter, and even thermal runaway problems occur at an elevated operating temperature. However, operating at too low a temperature may lower the conductivity of the electrolyte and the ability to conduct active ions, resulting an increase of the impedance, and a decrease in the capacity of the lithium-ion batteries.
Conventionally, the cell is positioned to improve the fluid flow path and increase the heat dissipation. The battery casing may also be improved by replacing the aluminum alloy shell material with the composite of thermoelectric material and aluminum, and by adding a plurality of heat dissipating ribs to the side of the battery casing. The electrode plate may also be extended into the electrolyte to transmit heat energy to the battery casing through the electrolyte and then to the outside environment. Although some heat is dissipated, the heat dissipation efficiency is generally low because the heat cannot be directly discharged from the electrode plates, the main heat generating component, to the outside environment. Therefore, a new design of a cylindrical lithium-ion battery is desired.
Implementations of the disclosure will now be described, by way of embodiments only, with reference to the drawings.
Referring to
By stacking the heat conducting and collecting bodies 5 to form the heat converging path 11 and heating the heat converging path 11 through the thin-film heater 8, the internal temperature of the battery 100 is increased, thereby avoiding low working efficiency and low service life of the battery 100 caused by a low internal temperature. Furthermore, the heat energy can also quickly exit out of the battery 100 through the heat converging path 11, thereby maintaining the temperature of the battery 100 within a suitable range. The heat conducting and collecting body 5 can be integrally formed with the positive electrode plate, which simplifies the manufacturing process and increase the manufacturing efficiency.
In at least one embodiment, the heat conducting and collecting bodies 5 overlap with each other. The heat conducting and collecting bodies 5 are connected together by welding, thereby forming the heat converging path 11. That is, the heat conducting and collecting bodies 5 can be connected together without any extra component. The welding can be ultrasonic welding, laser welding, or friction welding. In another embodiment, the heat conducting and collecting bodies 5 can also be connected together by bolting or riveting.
Moreover, referring to
In other embodiments, the heat conducting and collecting bodies 5 can also be parallel to the positive active material layers 410. That is, the heat conducting and collecting bodies 5 are not bent towards each other.
A fluid-containing pipe 6 is connected to the heat converging path 11. In at least one embodiment, the heat converging paths 11 (fluid-containing pipe 6) can be disposed at an end of the battery 100 having the positive terminal post 3 or opposite to the positive terminal post 3. The heat converging path 11 can also be disposed at a side of the battery 100. When the number of the at least one heat converging paths 11 is greater than one, the heat converging paths 11 disposed at the end of the positive terminal post 3 can be one or more than one.
In at least one embodiment, referring to
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In at least one embodiment, at least a portion of the heat conducting and collecting bodies 5 defines a plurality of holes (not shown). The holes can pass through the heat conducting and collecting body 5, and have a mesh structure or a 3D internal structure. In another embodiment, at least a portion of the heat conducting and collecting bodies 5 can define a concave and convex surface. As such, the heat conducting performance of the heat conducting and collecting body 5 is improved.
Referring to
In at least one embodiment, a second heat exchanging device 12 is connected to the heat converging path 11 by welding. The second heat exchanging device 12 can maintain the temperature of the heat converging path 11 within a suitable range, thereby avoiding damages to the battery 100. Furthermore, the heat converging path 11 and the second heat exchanging device 12 are connected together without any extra component, which also facilitates the connection. In another embodiment, the heat converging path 11 and the second heat exchanging device 12 can also be connected together by bolting, gluing, or riveting, which allows the connection to be stable. In another embodiment, the heat converging path 11 can also be directly connected to the outer casing 1. The outer casing 1 then serves as a heat sink to allow the heat energy on the heat converging path 11 to be delivered to the outer casing 1.
In at least one embodiment, the heat conducting and collecting body 5 can have an insulating layer (not shown) on a surface thereof. As such, a short circuit in the battery 100 and concomitant damage can be avoided.
In at least one embodiment, the heat conducting and collecting body 5 can protrude from the positive electrode plate 41, which facilitates the conduction and dissipation of the heat energy. Portions of the heat conducting and collecting body 5 protruding from the positive electrode plate 41 are further inserted into the electrolyte 13 received in the outer casing 1. As such, the heat energy from the heat conducting and collecting body 5 can be conducted into the electrolyte 13 and further to the external surface of the battery 100. Therefore, the heat energy is prevented from being accumulated in the battery 100 due to poor heat conduction of the separator 42. Furthermore, the heat energy in the electrolyte 13 can further quickly move to the positive and the negative electrode plates 41, 43, which prevents the temperature of the positive and the negative electrode plates 41, 43 from being too low. In another embodiment, the heat conducting and collecting body 5 can also be recessed with respect to the negative electrode plate 43, which saves the internal space of the battery 100, and further increases the capacity of the battery 100 in casing of a certain size.
In at least one embodiment, a third heat exchanging device 14 is disposed in the electrolyte 13 for heating or cooling the electrolyte 13. The electrolyte 13 can in turn heat or cool the heat conducting and collecting bodies 5, thereby maintaining the temperature of the battery 100 within a suitable range.
In an embodiment, an interconnecting portion 51 is formed between the heat conducting and collecting body 5 and the negative electrode plate 43. A thickness of the entirety of the heat conducting and collecting body 5 is same of that of the interconnecting portion 51. As such, the heat conducting property of the heat conducting and collecting body 5 is improved, and the manufacturing process is simplified.
In at least one embodiment, a first temperature sensor 15 is disposed on the heat converging path 11, which can sense the temperature of the heat converging path 11. Furthermore, a second temperature sensor 16 is disposed on the second heat exchanging device 12, which can sense the temperature of the second heat exchanging device 12. The first and the second temperature sensors 15, 16 can be thin-film temperature sensors.
In at least one embodiment, the positive active material of the positive active material layer 410 is lithium iron phosphate, lithium cobalt oxide, lithium manganate, or a ternary material. The negative active material of the negative active material layers 430 is carbon, tin-based negative material, transition metal nitride containing lithium or alloy.
Implementations of the above disclosure will now be described by way of embodiments only. It should be noted that devices and structures not described in detail are understood to be implemented by the general equipment and methods available in the art.
It is to be understood, even though information and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the present embodiments, the disclosure is illustrative only; changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the present embodiments to the full extent indicated by the plain meaning of the terms in which the appended claims are expressed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201710511981.X | Jun 2017 | CN | national |
This application claims all benefits accruing under 35 U.S.C. § 119 from China Patent Application No. 201710511981.X, filed on Jun. 28, 2017 in the China National Intellectual Property Administration, the content of which is hereby incorporated by reference. This application is a continuation under 35 U.S.C. § 120 of international patent application PCT/CN2018/093103 filed Jun. 27, 2018.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/CN2018/093103 | Jun 2018 | US |
| Child | 16727712 | US |
