Low-temperature rechargeable lithium battery structure

Abstract

The utility model discloses a low-temperature rechargeable lithium battery structure in the field of new energy batteries, which comprises a battery body with a charging port, a preheating device is wrapped outside the battery body, the preheating device comprises a shell, a wrapping group is arranged at the top of the shell, one end of the wrapping group is wrapped at the charging port, and the other end of the wrapping group is wrapped at the charging port. The other end of the package group is electrically connected with a variable-temperature ganged switch, the variable-temperature ganged switch comprises a first wiring switch and a second wiring switch, the first wiring switch is connected to the package group, and the second wiring switch is connected to the heating assembly. According to the technical scheme, an access circuit is adjusted through the variable-temperature ganged switch, when the temperature is too low, the current supplies power to the heating assembly firstly, the heating assembly after power supply generates heat to heat the shell, and the heat of the heated shell is conducted to the battery, so that the charging environment is improved.

Description

Technical Field

[0001] The utility model belongs to the field of new energy batteries, in particular to a low-temperature rechargeable lithium battery structure. Background Art

[0002] There are certain risks in charging lithium-ion batteries in low-temperature environments. As the temperature decreases, the electrochemical reaction and solid diffusion slow down. On the one hand, the material lattice shrinks, and the lithium ions cannot squeeze into the graphite layer in time, so they directly get electrons on the negative electrode surface and become metallic lithium, which becomes a conversion reaction (the reaction potential is lower than the intercalation reaction, which can be understood as more difficult to occur, but the diffusion of the intercalation reaction material is difficult, making the conversion reaction easy to occur at low temperatures). The uneven growth of low-temperature lithium precipitation can easily form lithium dendrites, and large lithium dendrites can pierce the diaphragm and even cause functional failure.

[0003] Secondly, at low temperatures, the lattices of the positive and negative electrode materials shrink, charge transfer and solid phase diffusion become slower, and Li ions are more difficult to deintercalate and embed. At the same time, it becomes more difficult to diffuse in the electrolyte, which together leads to fewer Li ions on the electrode surface area and in the electrolyte, making the electrode polarization larger. In addition, at low temperatures, the ohmic internal resistance of lithium-ion batteries will increase.

[0004] From the above principle, it can be seen that when lithium batteries are charged at low temperatures, not only will the capacitance decrease, but the service life of the lithium batteries will also be affected. Utility Model Content

[0005] In order to solve the problem that the capacitance of lithium batteries decreases due to low-temperature charging, the utility model aims to provide a low-temperature rechargeable lithium battery structure.

[0006] In order to achieve the above-mentioned purpose, the technical scheme of the utility model is as follows: a low-temperature rechargeable lithium battery structure, comprising a battery body with a charging port, the battery is wrapped with a preheating device on the outside, the preheating device comprises a shell, the top of the shell is provided with a wrapping group, one end of the wrapping group is wrapped around the charging port, and the other end of the wrapping group is electrically connected to a variable temperature double switch, the variable temperature double switch comprises a first wiring switch and a second wiring switch, the first wiring switch is connected to the wrapping group, and the second wiring switch is connected to the heating component;

[0007] The variable temperature double switch includes a horizontal support, and a first wiring switch and a second wiring switch are respectively arranged on both sides of the width of the support. A rotating component is provided in the middle position of the support, and the rotating component is connected to a knife switch. The movement stroke of the knife switch contacts the first wiring switch and the second wiring switch respectively. The rotating component includes a circular shell, and the circular shell has a first gear and a second gear coaxially connected therein. The first gear is meshed with a rack, and the second gear is connected to the knife switch. An opening is provided at the overlapping position of the circular shell and the first gear, and the rack passes through the opening.

[0008] The heating group includes but is not limited to electric heating wires or heating rods.

[0009] The following beneficial effects are achieved by adopting the above scheme: Compared with the existing technology of direct low-temperature charging, the access circuit is adjusted through a variable temperature double switch in this technical scheme. When the temperature is too low, the current first powers the heating component. After power supply, the heating component generates heat to heat the shell. The heated shell conducts heat to the battery, thereby improving the charging environment.

[0010] Furthermore, one end of the rack away from the circular shell is connected to a pressure shaft tube, which includes a sheath, and a sealing plate is slidably connected inside the sheath. The sealing plate divides the sheath into a closed chamber and an open chamber. The closed chamber is filled with expansion fluid, and the sealing plate is connected to the rack on one side facing the open chamber.

[0011] The swelling fluid includes, but is not limited to, liquids that expand when heated and contract when cooled, such as mercury, alcohol or thermosensitive gel.

[0012] Furthermore, the package group includes an insulating layer, a charging connector is inserted into the middle position of the insulating layer, and the charging connector contacts the charging port.

[0013] Furthermore, the outer surface of the shell is provided with corrugated grooves.

[0014] Beneficial effects: The shell is easy to hold or carry, and the corrugated grooves are convenient for storing heat energy.

[0015] Furthermore, the charging connector is provided with a sulfur / Co-mesoporous bio-carbon composite layer, a conductive carbon black layer, a polyvinylidene fluoride layer, an N-methyl-2-pyrrolidone layer and an aluminum foil layer from the inside to the outside; wherein the weight ratio of the sulfur / Co-mesoporous bio-carbon composite layer, the conductive carbon black layer and the polyvinylidene fluoride layer is 7:2:1.

[0016] Furthermore, the aluminum foil layer includes an electrode sheet, and the average sulfur loading of the electrode sheet is 2 mg / cm 2 .

[0017] 1. In this technical solution, a mesoporous biocarbon composite layer is added to produce a pore structure, thereby obtaining a metal-macroporous carbon composite structure with a large surface area, high porosity and enhanced conductivity, thereby producing good electrical conductivity and high porosity.

[0018] 2. At the same time, the sulfur / Co-mesoporous biocarbon composite layer can serve as an active site for adsorption and catalysis to effectively limit the shuttle effect caused by the dissolution of polysulfides, greatly improving the long-cycle performance of the charging interface and the electrochemical performance under high sulfur loading.

[0019] 3. The highly porous structure provides sufficient space for volume changes during the cycle. The prepared sulfur composite electrode exhibits significantly improved electrochemical performance, and can obtain strong cycle performance and good rate performance during charging. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of an embodiment of the utility model;

[0021] Figure 2 for Figure 1 Internal structure diagram;

[0022] Figure 3 for Figure 2 Structural diagram of a medium variable temperature double switch. DETAILED DESCRIPTION

[0023] The following is further described in detail through specific implementation methods:

[0024] The reference numerals in the drawings of the specification include: battery body 1, shell 2, corrugated groove 3, insulating layer 4, charging connector 5, support 6, first wiring switch 7, second wiring switch 8, knife switch 9, round shell 10, first gear 11, second gear 12, rack 13, pressure shaft tube 14, sealing plate 15, closed chamber 16, open chamber 17, expansion liquid 18.

[0025] The embodiment is basically as shown in the attached Figure 1 and Figure 2 As shown: The embodiment is basically as shown in the attached Figure 1 and Figure 2 As shown: a low-temperature rechargeable lithium battery structure includes a battery body 1 with a charging port, the battery is wrapped with a preheating device on the outside, the preheating device includes a shell 2, the outer surface of the shell 2 has a corrugated groove 3, the top of the shell 2 has a wrapping group, the wrapping group includes an insulating layer 4, a charging connector 5 is inserted in the middle of the insulating layer 4, the charging connector 5 contacts the charging port, one end of the wrapping group is wrapped around the charging port, and the other end of the wrapping group is electrically connected to a variable temperature double switch, the variable temperature double switch includes a first wiring switch 7 and a second wiring switch 8, the first wiring switch 7 is connected to the wrapping group, and the second wiring switch 8 is connected to the heating component;

[0026] Please refer to Figure 3 The variable temperature double switch includes a horizontal support 6, and a first wiring switch 7 and a second wiring switch 8 are respectively arranged on both sides of the width of the support 6. A rotating component is provided in the middle position of the support 6, and the rotating component is connected to a knife switch 9. The movement stroke of the knife switch 9 contacts the first wiring switch 7 and the second wiring switch 8 respectively. The rotating component includes a round shell 10, and the round shell 10 has a first gear 11 and a second gear 12 coaxially connected therein. The first gear 11 is meshed with a rack 13, and the second gear 12 is connected to the knife switch 9. An opening is provided at the overlap of the round shell 10 and the first gear 11, and the rack 13 passes through the opening.

[0027] The end of the rack 13 away from the round shell 10 is connected to a pressure shaft tube 14, which includes a sheath, and a sealing plate 15 is slidably connected inside the sheath. The sealing plate 15 divides the sheath into a closed chamber 16 and an open chamber 17. The closed chamber 16 is filled with an expansion fluid 18, and the sealing plate 15 is connected to the rack 13 on one side facing the open chamber 17.

[0028] The specific implementation process is as follows: In order to avoid the impact of low-temperature charging on the battery when this technical solution is used, a preheating device is used to improve the charging environment, but in order to avoid the natural phenomenon caused by the preheating device also preheating the battery at room temperature, the preheating device is temperature-controlled. When the sealed chamber 16 is designed to leave the factory, the knife 9 contacts the first wiring switch 7 in the natural state.

[0029] The limiting process is as follows: A. When in a low temperature environment, the liquid in the closed chamber 16 contracts, that is, the height of the liquid decreases, and the hydraulic pressure decreases. Since the pressure in the closed chamber 16 is constant, when the hydraulic pressure decreases, the external pressure pushes the sealing plate 15 backward to compress the gas volume in the closed chamber 16, thereby maintaining the constant pressure between the closed chamber 16 and the outside. The retreating sealing plate 15 drives the rack 13 and the first gear 11 to rotate in turn. At this time, the coaxial second gear 12 during the rotation of the first gear 11 will drive the knife 9 to deflect. During this process, the knife 9 is connected to the second wiring switch 8. Even if the temperature continues to drop, the position of the second wiring switch 8 will limit the maximum stroke of the knife 9 to prevent the knife 9 from deviating from the support 6.

[0030] Since the switch 9 is connected to the second wiring switch 8, the charging power supply, the wrapping group, the temperature-variable double switch and the heating component form a closed loop, while the charging power supply, the wrapping group, the temperature-variable double switch and the battery body 1 are disconnected. Therefore, the current first supplies power to the heating component, and the heating component after power supply generates heat to heat the shell 2, and the heated shell 2 conducts heat to the battery, thereby improving the charging environment.

[0031] B. When in a room temperature environment or after heating is completed, the liquid in the closed chamber 16 expands, that is, the height of the liquid increases, and the hydraulic pressure increases. Since the pressure in the closed chamber 16 is constant, when the hydraulic pressure increases, the external pressure pushes the sealing plate 15 forward to increase the volume of the closed chamber 16, and the volume of the gas in the closed chamber 16 expands, thereby maintaining the constant pressure of the closed chamber 16 and the external pressure. During the forward process, the sealing plate 15 drives the rack 13 and the first gear 11 to rotate in turn. At this time, the coaxial second gear 12 during the rotation of the first gear 11 will drive the knife 9 to deflect. During this process, the knife 9 is connected to the first wiring switch 7, and a closed loop is formed between the charging power supply, the package group, the temperature-changing double switch and the battery body 1, which is convenient for charging.

[0032] C. When the temperature drops during charging, proceed to step A.

[0033] Embodiment 2

[0034] The difference between this embodiment and the above embodiment is that the charging connector 5 is provided with a sulfur / Co-mesoporous biocarbon composite layer, a conductive carbon black layer, a polyvinyl difluoride layer, an N-methyl-2-pyrrolidone layer and an aluminum foil layer from the inside to the outside in sequence; wherein the weight ratio of the sulfur / Co-mesoporous biocarbon composite layer, the conductive carbon black layer and the polyvinyl difluoride layer is 7:2:1. The aluminum foil layer includes an electrode sheet, and the average sulfur loading of the electrode sheet is 2 mg / cm 2 .

[0035] Adding a mesoporous biocarbon composite layer produces a pore structure, thereby obtaining a metal-macroporous carbon composite structure with a large surface area, high porosity and enhanced conductivity. This results in good conductivity and high porosity. At the same time, the sulfur / Co-mesoporous biocarbon composite layer can serve as an active site for adsorption and catalysis to effectively limit the shuttle effect caused by the dissolution of polysulfides, greatly improving the long cycle performance of the charging interface and the electrochemical performance under high sulfur loading. The highly porous structure provides sufficient space for volume changes during the cycle. The prepared sulfur composite electrode exhibits significantly improved electrochemical performance, and can obtain strong cycle performance and good rate performance during charging.

[0036] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0037] The above is only an embodiment of the utility model. The common sense such as the known specific structure and characteristics in the scheme is not described in detail here. The ordinary technicians in the relevant field know all the common technical knowledge in the technical field of the utility model before the application date or priority date, can obtain all the existing technologies in the field, and have the ability to apply the conventional experimental means before that date. The ordinary technicians in the relevant field can improve and implement this scheme in combination with their own abilities under the enlightenment given by this application. Some typical known structures or known methods should not become obstacles for ordinary technicians in the relevant field to implement this application. It should be pointed out that for the technicians in this field, without departing from the structure of the utility model, several deformations and improvements can be made, which should also be regarded as the protection scope of the utility model, which will not affect the effect of the implementation of the utility model and the practicality of the patent. The protection scope required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to explain the content of the claims.

Claims

1. A low-temperature rechargeable lithium battery structure, comprising a battery body with a charging port, characterized in that: The battery is wrapped with a preheating device on the outside, the preheating device includes a shell, the top of the shell is provided with a wrapping group, one end of the wrapping group is wrapped around the charging port, the other end of the wrapping group is electrically connected to a variable temperature double switch, the variable temperature double switch includes a first wiring switch and a second wiring switch, the first wiring switch is connected to the wrapping group, and the second wiring switch is connected to the heating component; The variable temperature double switch includes a horizontal support, and a first wiring switch and a second wiring switch are respectively arranged on both sides of the width of the support. A rotating component is provided in the middle position of the support, and the rotating component is connected to a knife switch. The movement stroke of the knife switch contacts the first wiring switch and the second wiring switch respectively. The rotating component includes a circular shell, and the circular shell has a first gear and a second gear coaxially connected therein. The first gear is meshed with a rack, and the second gear is connected to the knife switch. An opening is provided at the overlapping position of the circular shell and the first gear, and the rack passes through the opening.

2. A low-temperature rechargeable lithium battery structure according to claim 1, characterized in that: The end of the rack away from the circular shell is connected to a pressure shaft tube, which includes a sheath, and a sealing plate is slidably connected inside the sheath. The sealing plate divides the sheath into a closed chamber and an open chamber. The closed chamber is filled with expansion fluid, and the side of the sealing plate facing the open chamber is connected to the rack.

3. A low-temperature rechargeable lithium battery structure according to claim 1, characterized in that: The package group includes an insulating layer, a charging connector is inserted into the middle of the insulating layer, and the charging connector contacts the charging port.

4. A low-temperature rechargeable lithium battery structure according to claim 1, characterized in that: The outer surface of the shell is provided with corrugated grooves.

5. A low-temperature rechargeable lithium battery structure according to claim 3, characterized in that: The charging connector is provided with a sulfur / Co-mesoporous bio-carbon composite layer, a conductive carbon black layer, a polyvinylidene fluoride layer, an N-methyl-2-pyrrolidone layer and an aluminum foil layer from the inside to the outside; the weight ratio of the sulfur / Co-mesoporous bio-carbon composite layer, the conductive carbon black layer and the polyvinylidene fluoride layer is 7:2:

1.

6. A low-temperature rechargeable lithium battery structure according to claim 5, characterized in that: The aluminum foil layer includes the electrode sheet, and the average sulfur loading of the electrode sheet is 2 mg / cm 2 .

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