A cathode material for a lithium-ion battery and a lithium-ion battery

Abstract

The present invention discloses a cathode material for a lithium-ion battery and a lithium-ion battery. The lithium-ion battery includes a first housing, and a first storage bin and a second storage bin are arranged inside the first housing. A first battery cell and a second battery cell are respectively installed in the first storage bin and the second storage bin. A controller is further installed on the first housing, and the controller is used for monitoring and controlling the current delivery states of the first battery cell and the second battery cell. An opening matching the second storage bin is provided on the first housing, and a support assembly matching the opening is installed on the first housing. The lithium-ion battery further includes an ultrasonic detection mechanism for detecting the first battery cell and the second battery cell, and the ultrasonic detection mechanism is used for detecting the internal states of the first battery cell and the second battery cell. Compared with the prior art, both the cathode material for a lithium-ion battery and the lithium-ion battery of the present invention are beneficial to extending the service life of the lithium-ion battery and greatly improving the safety of the lithium-ion battery during use.

Description

Technical Field

[0001] The present invention belongs to the technical field of batteries, and in particular relates to a lithium ion battery positive electrode material and a lithium ion battery. Background Art

[0002] As a widely used power source and energy storage device, lithium-ion batteries play an important role in the fields of electric vehicles and renewable energy storage. However, the overcharge and overload problems of lithium-ion batteries during the charging and discharging process lead to the formation of lithium dendrites inside the battery. Lithium dendrites are some irregular branch-like growth structures that are formed during the lithium ion deposition process. The formation of this structure not only destroys the uniformity and stability inside the battery, but also causes local short circuits inside the battery, significantly reducing the overall efficiency and performance of the battery. Especially in the case of over-discharge, the problem of lithium dendrites is more serious. The presence of lithium dendrites will greatly increase the rate of battery aging and damage, thereby seriously affecting the service life of the battery.

[0003] The local short circuit phenomenon caused by lithium dendrites not only has a negative impact on battery performance, but also further affects the safety of the battery. When lithium dendrites grow to a certain extent inside the battery, they may pierce the battery separator, causing battery bulging, gas leakage, etc. In addition, if lithium dendrites continue to grow inside the battery, they may eventually cause a short circuit, causing the internal temperature of the battery to rise sharply, posing a safety hazard, and may even cause thermal runaway and explosion of the battery, affecting the user's safety and the overall performance of the battery.

[0004] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0005] The object of the present invention is to provide a lithium ion battery positive electrode material and a lithium ion battery, which can solve the technical problems raised in the above background technology.

[0006] In order to achieve the above object, a technical solution provided by a specific embodiment of the present invention is as follows:

[0007] A lithium ion battery positive electrode material, wherein a slow decay layer is arranged on the surface of the lithium ion battery positive electrode.

[0008] In order to achieve the above object, a technical solution provided by a specific embodiment of the present invention is as follows:

[0009] A lithium-ion battery, comprising a lithium-ion battery cathode material, further comprising a first housing. A first storage bin and a second storage bin are arranged inside the first housing. A first battery cell and a second battery cell are respectively installed in the first storage bin and the second storage bin. A controller is further installed on the first housing. The controller is used to monitor and control the current delivery states of the first battery cell and the second battery cell. An opening matching the second storage bin is arranged on the first housing. A support assembly matching the opening is installed on the first housing. The support assembly includes a base. A convex edge matching the inner wall of the second storage bin is fixedly connected to the base. The base is detachably installed on the first housing. An electric telescopic rod is fixedly connected to the middle of the base. A support plate is fixedly connected to the output end of the electric telescopic rod. A suction cup is fixedly connected to the support plate. A protection assembly matching the second battery cell is installed between the support plate and the base. The lithium-ion battery further includes an ultrasonic detection mechanism for detecting the first battery cell and the second battery cell. The ultrasonic detection mechanism is used to detect the internal states of the first battery cell and the second battery cell.

[0010] In one or more embodiments of the present invention, the protection assembly includes a first box body. A connecting plate is slidably connected inside the first box body. A connecting rod is fixedly connected to the upper end of the connecting plate. One end of the connecting rod penetrates through the top wall of the first box body. A first medium is filled inside the first box body. The first medium is located between the connecting plate and the bottom wall of the first box body. A second box body is further installed on one side of the base where the first box body is located. A second medium is filled inside the second box body. A first connecting pipe is fixedly connected between the first box body and the second box body. One end of the first connecting pipe is located inside the second box body. A plurality of second through holes are opened on the first connecting pipe located inside the second box body. A plurality of discharge holes are opened on the support plate. A second connecting pipe matching the discharge holes is installed between the support plate and the second box body. The first medium and the second medium are mixed in the second box body and then discharged from the discharge holes.

[0011] In one or more embodiments of the present invention, a convex strip is fixedly connected to the inner wall of the second storage bin. A plurality of arched protrusions are fixedly connected to the convex strip.

[0012] In one or more embodiments of the present invention, a second housing is fixedly connected to the first housing. The controller is located inside the second housing. A first electrical connection line is installed on the first battery cell. A pole column is installed on the second battery cell. A second electrical connection line matching the pole column is installed on the controller. The first electrical connection line is respectively connected to the controller. The second battery cell is connected to the controller through the cooperation of the pole column and the second electrical connection line.

[0013] In one or more embodiments of the present invention, a pulse repair component is installed in the second housing, and the pulse repair component realizes the treatment of lithium dendrites in the first battery cell and the second battery cell by means of pulses.

[0014] In one or more embodiments of the present invention, the ultrasonic detection mechanism is installed in the second housing. The ultrasonic detection mechanism includes an ultrasonic detector. A first detection probe and a second detection probe that match the ultrasonic detector are installed in the first housing. The first detection probe is used to detect the first battery cell, and the second detection probe is used to detect the second battery cell.

[0015] In one or more embodiments of the present invention, a liquid supplementing mechanism is installed in the second housing. The liquid supplementing mechanism is used to supplement repair liquid into the first battery cell or the second battery cell. The liquid supplementing mechanism includes a storage tank. The repair liquid is stored in the storage tank. An infusion tube is installed on the storage tank. One end of the infusion tube far from the storage tank is fixedly connected with a connector that matches the second battery cell. The connector is slidably connected to the second housing. One end of the connector penetrates through the second housing and the first housing. One end of the connector is located in the second storage bin. A bracket is installed on the second housing, and an electromagnet is installed on the bracket. A magnet that matches the electromagnet is fixedly connected to the connector.

[0016] In one or more embodiments of the present invention, the second battery cell includes a first electrode sheet and a separator. A liquid injection tube is arranged between the first electrode sheet and the separator. The liquid injection tube includes a third connecting tube and a fourth connecting tube. The fourth connecting tube is slidably connected in the third connecting tube. A first liquid outlet hole and a second liquid outlet hole are respectively formed in the third connecting tube and the fourth connecting tube. The first liquid outlet hole and the second liquid outlet hole are offset in the up-and-down direction. A tensioning mechanism that matches the fourth connecting tube is installed on the connector.

[0017] In one or more embodiments of the present invention, a micro battery for supplying power to electronic components in the second housing is installed in the second housing.

[0018] Compared with the prior art, in a lithium-ion battery cathode material and a lithium-ion battery of the present invention, by arranging a second battery cell in the lithium-ion battery, when overcharging or over-discharging occurs, the second battery cell bears the overcharged or over-discharged electric quantity, so that lithium dendrites grow in the second battery cell, and the lithium dendrites in the second battery cell are processed by means of detection and treatment, avoiding situations such as thermal runaway and explosion of the lithium-ion battery caused by lithium dendrites. The second battery cell can be replaced. The second battery cell can exert its performance to the extreme. Without affecting the normal use of the lithium-ion battery, it can also ensure the service life of the lithium-ion battery, is easy to replace, reduces the replacement cost of the lithium-ion battery, and the safety can also be greatly improved;

[0019] The cathode material of the lithium-ion battery can not only reduce the oxidation and decomposition of the electrolyte under high voltage, but also prevent the dissolution of transition metal ions, delay the collapse of the cathode material structure, form a dense layer to block the direct contact between the electrolyte and the cathode, and reduce the attack of corrosive substances such as HF. Brief Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0021] Figure 1 It is a schematic structural diagram of a lithium-ion battery in an embodiment of the present invention;

[0022] Figure 2 It is a cross-sectional view of the first housing in an embodiment of the present invention;

[0023] Figure 3 It is a partial cross-section of a lithium-ion battery in an embodiment of the present invention Figure 1 ;

[0024] Figure 4 It is a schematic structural diagram of the support assembly in an embodiment of the present invention;

[0025] Figure 5 It is a partial cross-sectional view of the support assembly in an embodiment of the present invention;

[0026] Figure 6 It is a schematic structural diagram of the rib in an embodiment of the present invention;

[0027] Figure 7 It is a partial cross-section of a lithium-ion battery in an embodiment of the present invention Figure 2 ;

[0028] Figure 8 It is a schematic diagram of the partial structure of a lithium-ion battery in an embodiment of the present invention;

[0029] Figure 9 It is Figure 8 the structural diagram at position A in

[0030] Figure 10 It is Figure 8 the structural diagram at position B in

[0031] Figure 11 It is a schematic diagram of the partial structure of the second electrical connection line in an embodiment of the present invention;

[0032] Figure 12Schematic diagram of the partial structure of the second battery cell in an embodiment of the present invention Figure 1 ;

[0033] Figure 13 Schematic diagram of the partial structure of the second battery cell in an embodiment of the present invention Figure 2 ;

[0034] Figure 14 is Figure 13 Schematic diagram of the structure at position C in

[0035] Figure 15 Partial cross-sectional view of the liquid injection pipe in an embodiment of the present invention

[0036] Figure 16 Pulse repair parameter data diagram of a lithium-ion battery in an embodiment of the present invention

[0037] Figure 17 Schematic diagram of the structure of the positive electrode material of a lithium-ion battery in an embodiment of the present invention

[0038] Main reference numeral description:

[0039] 1. First housing; 101. First storage chamber; 102. Second storage chamber; 103. First threaded hole; 2. Second housing; 3. First battery cell; 301. First electrical connection wire; 4. Second battery cell; 401. First electrode plate; 402. Separator; 403. Second electrode plate; 404. Terminal; 5. Support assembly; 6. Base; 601. First through hole; 7. Flange; 8. Bolt; 9. Electric telescopic rod; 10. Support plate; 1001. Discharge hole; 11. Suction cup; 12. Protection assembly; 13. First box body; 14. Connecting plate; 15. Connecting rod; 16. First connecting pipe; 1601. Second through hole; 17. Valve; 18. Second box body; 19. Second connecting pipe; 20. Pressure relief valve; 21. Rib; 2101. Arch-shaped protrusion; 22. Controller; 23. Positive electrode connection post; 24. Negative electrode connection post; 25. Third electrical connection wire; 26. Pulse repair assembly; 27. First pulse repairer; 28. Second pulse repairer; 29. Ultrasonic detection mechanism; 30. Ultrasonic detector; 31. First detection probe; 32. Second detection probe; 33. Liquid supplement mechanism; 34. Storage tank; 35. Infusion pipe; 36. Pump; 37. Bracket; 38. Electromagnet; 39. Magnet; 40. Connector; 4001. Tensioning mechanism; 41. Micro battery; 42. Liquid injection pipe; 43. Third connecting pipe; 4301. First liquid outlet hole; 44. Fourth connecting pipe; 4401. Second liquid outlet hole; 45. Damping layer; 46. Second electrical connection wire. Detailed implementation manners

[0040] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0041] As Figures 1 to 7 shown, a lithium-ion battery in an embodiment of the present invention includes a first housing 1. A first storage chamber 101 and a second storage chamber 102 are provided in the first housing 1, and the first storage chamber 101 and the second storage chamber 102 are not communicated with each other. A first battery cell 3 matching the first storage chamber 101 and a second battery cell 4 matching the second storage chamber 102 are installed in the first housing 1. A controller 22 is installed on the first housing 1. The controller 22 can control and detect the output and input states of the first battery cell 3 and the second battery cell 4. A first electrical connection line 301 matching the controller 22 is installed on the first battery cell 3. A terminal 404 matching the controller 22 is installed on the second battery cell 4. A second electrical connection line 46 matching the terminal 404 is installed on the controller 22, and the second electrical connection line 46 and the terminal 404 are in contact by a contact point.

[0042] Specifically, the controller 22 controls the power of the first battery cell 3 to be maintained between 20% and 80%, and does not control the remaining power of the second battery cell 4. To avoid the decomposition of the electrolyte due to the lithium battery being fully charged for a long time, the first battery cell 3 stops charging when it is charged to 80% - 90%. When the power is lower than 20%, the first battery cell 3 stops outputting, and only the second battery cell 4 outputs. And the output voltage of the first battery cell 3 is relatively stable to ensure the temperature of the first battery cell 3. When the lithium-ion battery is under load, the second battery cell 4 provides more voltage to protect the first battery cell 3 and extend the service life of the first battery cell 3.

[0043] The second battery cell 4 acts as a bodyguard for the first battery cell 3, enabling the first battery cell 3 not to be overloaded and not to be at a high temperature. Therefore, during the normal use of the lithium-ion battery, the second battery cell 4 needs to output more voltage. During charging, the overcharging current also enters the second battery cell 4. Therefore, the second battery cell 4 is prone to damage. With the detachable second battery cell 4, when the second battery cell 4 is damaged, it can be replaced to extend the service life of the lithium-ion battery. At the same time, it can also enable the lithium-ion battery to meet the working requirements of various loads.

[0044] As Figures 1 to 6As shown in the figure, an opening is provided at the lower end of the second storage bin 102. The second battery cell 4 is placed into the second storage bin 102 through the opening, and a support assembly 5 matching the opening is installed on the first housing 1. The support assembly 5 blocks the opening of the first housing 1 and can be sealed, so that the second battery cell 4 is fixed in the second storage bin 102.

[0045] As Figures 1 to 6 shown in the figure, the support assembly 5 includes a base 6. A convex edge 7 matching the inner wall of the second storage bin 102 is fixedly connected to the base 6. The outer wall of the convex edge 7 and the inner wall of the second storage bin 102 are in interference fit, and the base 6 seals the second storage bin 102. A plurality of first through holes 601 are provided on the base 6, and a first threaded hole 103 matching the first through holes 601 is provided on the first housing 1. A bolt 8 matching the first through holes 601 is installed on the base 6. The bolt 8 can pass through the first through holes 601 and be threadedly connected to the first threaded hole 103, that is, the base 6 and the first housing 1 are locked by the bolt 8. An electric telescopic rod 9 is fixedly connected to the middle of the base 6. The output end of the electric telescopic rod 9 is fixedly connected to a support plate 10. A suction cup 11 matching the second battery cell 4 is fixedly connected to the support plate 10.

[0046] Specifically, since the second battery cell 4 is adsorbed on the suction cup 11, when the controller 22 detects an abnormality of the second battery cell 4, the electric telescopic rod 9 can descend. The descent of the electric telescopic rod 9 drives the support plate 10 to descend, and the second battery cell 4 on the support plate 10 will also be separated from the second electrical connection line 46. At this time, only the first battery cell 3 operates in the lithium-ion battery. Even if the second battery cell 4 is damaged, it will not affect the normal operation of the lithium-ion battery.

[0047] When installing the second battery cell 4, first adsorb the bottom wall of the second battery cell 4 on the suction cup 11, then insert the second battery cell 4 into the second storage bin 102, and complete the fixation of the base 6 and the first housing 1 through the bolt 8.

[0048] Preferably, in order to further improve the sealing effect of the support assembly 5, a sealing structure such as a sealing ring can also be provided between the convex edge 7 and the second storage bin 102.

[0049] As Figures 1 to 5 shown in the figure, a protection assembly 12 is fixedly connected between the support plate 10 and the base 6. The protection assembly 12 can fill a medium for protection in the second storage bin 102 when the second battery cell 4 is exposed to high temperature or damaged, so as to prevent the high temperature of the second battery cell 4 from being transmitted to the first battery cell 3 and affecting the first battery cell 3.

[0050] Specifically, as Figures 1 to 5As shown, the protection component 12 includes a first box body 13 and a second box body 18. Both the first box body 13 and the second box body 18 are fixedly connected to the base 6 and are located between the base 6 and the support plate 10. The first box body 13 is filled with a first medium, and the second box body 18 is filled with a second medium. After the first medium and the second medium are mixed, a heat insulation material will be formed and output to the second storage bin 102.

[0051] As Figure 5 shown, a connecting plate 14 is slidably connected inside the first box body 13. The outer wall of the connecting plate 14 is in contact with the inner wall of the first box body 13, and a seal can be formed. The upper end of the connecting plate 14 is fixedly connected to a connecting rod 15. The connecting rod 15 penetrates through the top wall of the connecting plate 14, and one end of the connecting rod 15 is located above the connecting plate 14. A first connecting pipe 16 is fixedly connected between the first box body 13 and the second box body 18. A valve 17 is installed on the first connecting pipe 16. The valve 17 is a physical pressure relief valve. When the connecting rod 15 is pressed downward, the connecting plate 14 moves downward in the first box body 13 along with the connecting rod 15. When the valve 17 bears too much pressure, the valve 17 will open, and the first medium enters the second box body 18 through the first connecting pipe 16 to react with the second medium to form a heat insulation material. A second connecting pipe 19 is installed on the second box body 18. The second connecting pipe 19 communicates with the support plate 10, and a plurality of discharge holes 1001 are formed in the support plate 10. The formed heat insulation material is output to the second storage bin 102 through the discharge holes 1001.

[0052] Specifically, the first medium and the second medium can be a combination of isocyanate and polyol, can also be a combination of sodium bicarbonate and an acidic substance, and can also be a combination of other media, as long as the temperature diffusion of the second battery cell 4 can be inhibited. Among them, the combination of isocyanate and polyol can form a closed-cell foam structure. This foam expands rapidly and can solidify to form a lightweight and high-strength heat insulation layer. The combination of sodium bicarbonate and an acidic substance generates carbon dioxide gas and foam. The foam and carbon dioxide gas are filled into the second storage bin 102, and can also play a certain heat insulation role.

[0053] As Figure 5 shown, a section of the first connecting pipe 16 is in an S shape and is located inside the second box body 18. A plurality of second through holes 1601 are formed in the part of the first connecting pipe 16 located inside the second box body 18, so that the first medium can be in full contact with the second medium, and the mixing reaction efficiency of the two is improved.

[0054] As Figures 1 to 3As shown, a pressure relief valve 20 is installed on the first housing 1. The pressure relief valve 20 is used to control the pressure in the second storage bin 102. When the pressure in the second storage bin 102 is too high, the pressure relief valve 20 will relieve the pressure to avoid the situation that excessive medium enters the second storage bin 102 and causes deformation of the first housing 1. If the medium can continuously be filled into the second storage bin 102, the pressure relief valve 20 will discharge the filled medium and take away the heat in the second storage bin 102.

[0055] To allow the medium to fully contact the second battery cell 4, as Figures 1 to 6 shown, a plurality of convex strips 21 are fixedly connected to the inner wall of the second storage bin 102. A plurality of arched protrusions 2101 are provided on the convex strips 21. When the second battery cell 4 is placed in the second storage bin 102, the arched protrusions 2101 can make a certain gap between the second battery cell 4 and the inner wall of the second storage bin 102, facilitating the passage of the medium. And the second battery cell 4 is adsorbed and fixed by a suction cup 11. The suction cup 11 protrudes from the surface of the support plate 10. There is also a gap between the second battery cell 4 and the support plate 10. The medium has good fluidity in the second storage bin 102.

[0056] As Figures 1 to 2 shown, a second housing 2 is fixedly connected to the first housing 1. The controller 22 is located inside the second housing 2. The second electrical connection line 46 passes through the second housing 2 and the first housing 1. One end of the second electrical connection line 46 protrudes from the inner top wall of the second storage bin 102. A positive connection post 23 and a negative connection post 24 are connected to the controller 22. A third electrical connection line 25 is connected between the positive connection post 23 and the negative connection post 24 and the controller 22. The positive connection post 23 and the negative connection post 24 are fixedly connected to the second housing 2.

[0057] By setting the second battery cell 4, the service life of the first battery cell 3 is extended. The second battery cell 4 is more likely to be in a vulnerable life state such as being under load or overcharged. As Figures 7 to 8 shown, a pulse repair component 26 is provided inside the second housing 2. The pulse repair component 26 includes a first pulse repairer 27 and a second pulse repairer 28. The first pulse repairer 27 and the second pulse repairer 28 are respectively installed on the first electrical connection line 301 and the second electrical connection line 46. With the presence of the first pulse repairer 27 and the second pulse repairer 28, the first battery cell 3 and the second battery cell 4 are charged in a pulse manner, which can greatly extend the service life of the first battery cell 3 and the second battery cell 4. Pulse current is used to eliminate or inhibit the growth of lithium dendrites. By the pulse current, the state of lithium dendrites can be changed to promote the uniform deposition of lithium and dissolve the existing lithium dendrites.

[0058] As Figures 7 to 8As shown, an ultrasonic detection mechanism 29 is installed inside the second housing 2. The ultrasonic detection mechanism 29 includes an ultrasonic detector 30. Inside the first housing 1, a first detection probe 31 and a second detection probe 32 that match the ultrasonic detector 30 are installed. The first detection probe 31 is used to detect the first battery cell 3, and the second detection probe 32 is used to detect the second battery cell 4. The detection data of the first detection probe 31 and the second detection probe 32 are transmitted to the ultrasonic detector 30, and the ultrasonic detector 30 then transmits the output to the controller 22. The controller 22 analyzes the data and then controls the output state of the ultrasonic detector 30 to enable the ultrasonic detector 30 to effectively process the lithium dendrites in the first battery cell 3 and the second battery cell 4.

[0059] When the pulse repair assembly 26 is in normal use, it charges the first battery cell 3 and the second battery cell 4 in a pulsed manner. When the ultrasonic detection mechanism 29 detects abnormal lithium dendrites in the first battery cell 3 and the second battery cell 4, the pulse repair assembly 26 intervenes and dissolves the lithium dendrites in the first battery cell 3 and the second battery cell 4 by changing the current density, pulse frequency, duty cycle, and pulse direction.

[0060] During repair, the pulsed method is used to preferentially process the spiky parts of the lithium dendrites. The curvature radius of the dendrite tip is small, and the current density is inversely proportional to the curvature radius. This characteristic needs to be utilized to concentrate energy to damage the tip. High-current pulses act preferentially on high-curvature regions, and the current density in low-curvature regions is relatively low to avoid damaging the main body of the electrode. Local Joule heating needs to be sufficient to melt / fracture the dendrites but avoid overall overheating. Taking preventive suppression, lithium dendrite repair, and emergency treatment as examples, the specific parameters are as Figure 16 shown. It should be noted that the pulse parameter settings need to follow the principle of "local high-energy action, global safety and controllability". Through the collaborative design of current density, pulse width, and frequency, the high-curvature lithium dendrite tips are preferentially damaged. In practical applications, experimental calibration, model simulation, and dynamic feedback need to be combined to balance the dendrite suppression effect with the battery life and the safety of battery use. Preferably, in the future, an intelligent BMS may also be developed to achieve a full-automatic closed-loop control of "detection → treatment → repair".

[0061] As Figures 7 to 15As shown in the figure, a liquid replenishing mechanism 33 is installed in the second housing 2. The liquid replenishing mechanism 33 is used for the final repair of the first battery cell 3 and the second battery cell 4. Among them, the liquid replenishing mechanism 33 includes a storage tank 34 filled with lithium trifluoromethanesulfonate. A liquid infusion pipe 35 is installed on the storage tank 34. A pump 36 is installed on the liquid infusion pipe 35. One end of the liquid infusion pipe 35 away from the storage tank 34 is installed with a connector 40. The connector 40 is perpendicular to the inner bottom wall of the second housing 2, and the connector 40 sequentially penetrates through the second housing 2 and the first housing 1 and is slidably connected to the second housing 2 and the first housing 1. A liquid injection pipe 42 matching the connector 40 is provided on the second battery cell 4. The liquid injection pipe 42 is inserted into the connector 40. When the connector 40 slides downward to connect with the liquid injection pipe 42, the lithium trifluoromethanesulfonate in the storage tank 34 can be transported to the liquid injection pipe 42 through the connector 40 by the pump 36, and then the lithium trifluoromethanesulfonate is transported into the second battery cell 4 by the liquid injection pipe 42.

[0062] As Figures 7 to 15 shown, the second battery cell 4 includes a first electrode plate 401, a separator 402, and a second electrode plate 403. The liquid injection pipe 42 is located between the separator 402 and the first electrode plate 401, and the liquid injection pipe 42 can also extend between the second electrode plate 403 and the separator 402. Since the liquid injection pipe 42 is located inside the second battery cell 4, the chemical stability, mechanical strength, thermal stability and the impact on the battery performance need to be considered comprehensively. The material of the liquid injection pipe 42 is generally ultra-high molecular weight polyethylene, polytetrafluoroethylene and other materials that have good tolerance to solvents, acids and alkalis and are suitable for the transportation of lithium trifluoromethanesulfonate. According to the different lithium-ion battery packs, the outer diameter of the liquid injection pipe 42 is generally 3-8 mm. It should be noted that when selecting materials, reactions with electrode materials or electrolytes should be avoided.

[0063] Specifically, as Figures 13 to 15As shown, the liquid injection pipe 42 includes a third connecting pipe 43 and a fourth connecting pipe 44. The fourth connecting pipe 44 is arranged inside the third connecting pipe 43, and the fourth connecting pipe 44 is slidably connected to the third connecting pipe 43. One end of the fourth connecting pipe 44 slightly protrudes from the third connecting pipe 43, and the fourth connecting pipe 44 is connected to the connecting head 40. A first liquid outlet hole 4301 is formed in the third connecting pipe 43, and a second liquid outlet hole 4401 is formed in the fourth connecting pipe 44. The first liquid outlet hole 4301 and the second liquid outlet hole 4401 are on a straight line, and the opening directions of the first liquid outlet hole 4301 and the second liquid outlet hole 4401 both face the first electrode sheet 401. When the fourth connecting pipe 44 slides in the third connecting pipe 43, the first liquid outlet hole 4301 and the second liquid outlet hole 4401 can be aligned. That is, lithium trifluoromethanesulfonate enters the fourth connecting pipe 44 through the connecting head 40. When the fourth connecting pipe 44 is completely filled with lithium trifluoromethanesulfonate, the fourth connecting pipe 44 slides in the third connecting pipe 43 to align the first liquid outlet hole 4301 and the second liquid outlet hole 4401. The lithium trifluoromethanesulfonate in the fourth connecting pipe 44 is discharged through the second liquid outlet hole 4401 and the first liquid outlet hole 4301, so that the lithium trifluoromethanesulfonate is sprayed onto the first electrode sheet 401 relatively evenly. The lithium trifluoromethanesulfonate is fully contacted with the electrolyte and the contact is uniform.

[0064] Among them, lithium trifluoromethanesulfonate optimizes the electrolyte performance, repairs or stabilizes the SEI film, improves ion transport, and thus repairs the battery performance. During the cycling of lithium batteries, the electrolyte will form an SEI film on the electrode surface. If the SEI film is unstable or ruptured, it will lead to capacity decay. Lithium trifluoromethanesulfonate may help repair or stabilize the SEI film, reduce side reactions, and extend the battery life. As a conductive salt, lithium trifluoromethanesulfonate can increase the ionic conductivity of the electrolyte, improve the transport of lithium ions, and thus enhance the battery performance, especially under high current density or low temperature conditions. It can also prevent short circuits by promoting uniform lithium deposition and reducing the formation of dendrites.

[0065] Furthermore, the total amount of lithium trifluoromethanesulfonate charged is generally 3 - 5 ml. The second liquid outlet hole 4401 and the first liquid outlet hole 4301 are micro-holes. When discharging lithium trifluoromethanesulfonate, the lithium trifluoromethanesulfonate is in the form of micro-bubbles. When the lithium trifluoromethanesulfonate contacts the first electrode sheet 401, the micro-nano bubbles burst, generating a certain amount of energy to strip part of the lithium dendrites on the surface of the separator 402.

[0066] Such as Figures 7 to 11As shown in the figure, a bracket 37 matching the connector 40 is fixedly connected inside the second housing 2. An electromagnet 38 is fixedly connected to the bracket 37, and a magnet 39 matching the electromagnet 38 is fixedly connected to the connector 40. The electromagnet 38 can change the positive and negative poles to control the up and down sliding of the bracket 37 on the first housing 1. Specifically, when the electromagnet 38 is positive, the electromagnet 38 and the magnet 39 are in contact with each other, and the second liquid outlet hole 4401 and the first liquid outlet hole 4301 are aligned. If the electromagnet 38 is negative, the electromagnet 38 and the magnet 39 repel each other, and the second liquid outlet hole 4401 and the first liquid outlet hole 4301 are in a misaligned state. In this state, the lithium trifluoromethanesulfonate in the fourth connecting pipe 44 will not be discharged from the injection pipe 42.

[0067] As Figure 11 shown, a tensioning mechanism 4001 matching the fourth connecting pipe 44 is installed on the inner wall of the connector 40. The tensioning mechanism 4001 can specifically be various mechanisms such as an airbag and hydraulic tensioning. When the connector 40 is in contact with the fourth connecting pipe 44, it is only necessary to make the connector 40 and the fourth connecting pipe 44 clamp. During the sliding process of the connector 40, it is only necessary to ensure that the connector 40 and the fourth connecting pipe 44 do not separate.

[0068] Since there are various electronic components arranged in the first housing 1 and the second housing 2, such as the electric telescopic rod 9, the electromagnet 38, the pump 36, etc., which all consume electricity during operation. In order to reduce the loss of the first battery cell 3 and the second battery cell 4, a micro battery 41 for supplying power to the electronic components in the second housing 2 and the first housing 1 is arranged in the second housing 2. The micro battery 41 is synchronously charged when the lithium-ion battery is charged.

[0069] When the lithium-ion battery is charged, it is pulse-charged in a preventive suppression state through the pulse repair component 26. When the lithium-ion battery is in a normal use state, the ultrasonic detection mechanism 29 intermittently or continuously detects the first battery cell 3 and the second battery cell 4, generally intermittently. When the battery is cycled 30 - 50 times, the ultrasonic detection mechanism 29 detects the lithium-ion battery once. If, among them, the first battery cell 3 and the second battery cell 4 enter the overcharge or over-discharge state multiple times, when the battery is cycled 10 - 30 times, the ultrasonic detection mechanism 29 detects the lithium-ion battery. In other words, the ultrasonic detection mechanism 29 triggers the detection state according to the use state of the first battery cell 3 and the second battery cell 4. The ultrasonic detection mechanism 29 can detect states such as the growth of lithium dendrites in the first battery cell 3 and the second battery cell 4. The results detected by the ultrasonic detection mechanism 29 are transmitted to the controller 22. The controller 22 judges the state of the lithium-ion battery according to the detection results, and adopts pulse parameters such as dendrite repair and emergency treatment during charging according to the states such as the growth of lithium dendrites in the lithium-ion battery to achieve the preliminary repair of the lithium-ion battery.

[0070] Since the first battery cell 3 is not overcharged or over-discharged, the second battery cell 4 substitutes for the first battery cell 3 to be overcharged and over-discharged. The state inside the second battery cell 4 becomes worse after long-term use, and the service life of the second battery cell 4 is shorter. Therefore, the ultrasonic detection mechanism 29 should detect the second battery cell 4 at a higher frequency than the first battery cell 3. When it is detected that the inside of the second battery cell 4 cannot be repaired by pulse repair, the liquid supplement mechanism 33 will supplement a certain amount of lithium trifluoromethanesulfonate into the second battery cell 4, and repair the inside of the second battery cell 4 with lithium trifluoromethanesulfonate.

[0071] If the second battery cell 4 is damaged or its capacitance is insufficient to meet the requirements, the support assembly 5 can be disassembled, and the second battery cell 4 installed in the second storage bin 102 can be taken out and replaced to ensure the service life of the lithium-ion battery and reduce the replacement cost of the lithium-ion battery. Through multiple self-repairs of the lithium-ion battery, the lithium-ion battery can be fully utilized.

[0072] By setting the second battery cell 4, the lithium-ion battery of the present invention allows the second battery cell 4 to bear the overcharged or over-discharged power during overcharging or over-discharging, causing lithium dendrites to grow inside the second battery cell 4, and dealing with the lithium dendrites inside the second battery cell 4 through detection and treatment methods to avoid situations such as thermal runaway and explosion of the lithium-ion battery caused by lithium dendrites. Moreover, the second battery cell 4 can be replaced and used as a backup battery cell. It can maximize its performance, ensure the service life of the lithium-ion battery without affecting its normal use, is easy to replace, reduces the replacement cost of the lithium-ion battery, and can greatly improve the safety.

[0073] A positive electrode material of a lithium-ion battery in an embodiment of the present invention includes a decay retardation layer 45 provided on the positive electrode of the lithium-ion battery. The decay retardation layer 45 can not only reduce the oxidation and decomposition of the electrolyte under high voltage, such as the gas generation and acid generation of carbonate solvents, but also help prevent the dissolution of transition metal ions, such as Ni³⁺ and Co³⁺, delay the collapse of the positive electrode material structure, form a dense layer to block the direct contact between the electrolyte and the positive electrode, and reduce the attack of corrosive substances such as HF. The decay retardation layer 45 is composed of the composite of lithium trifluoromethanesulfonate and inorganic substances such as Al2O3 and LiAlO2, and is constructed into a multi-layer structure by using sol-gel method or atomic layer deposition.

[0074] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, in any aspect, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention. Any reference signs in the claims should not be construed as limiting the claims involved.

[0075] In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment only contains an independent technical solution. This narrative manner of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A lithium-ion battery, characterized in that, It includes a decay - retardant layer, and the decay - retardant layer is disposed on the surface of the positive electrode of the lithium - ion battery. It further includes: A first housing, in which a first storage bin and a second storage bin are provided. A first battery cell and a second battery cell are respectively installed in the first storage bin and the second storage bin. A controller is also installed on the first housing, and the controller is used to monitor and control the current delivery status of the first battery cell and the second battery cell; An opening matching the second storage bin is provided on the first housing, and a support assembly matching the opening is installed on the first housing; The support assembly includes a base, and a convex edge matching the inner wall of the second storage bin is fixedly connected to the base. The base is detachably installed on the first housing; An electric telescopic rod is fixedly connected to the middle of the base, and a support plate is fixedly connected to the output end of the electric telescopic rod. A suction cup is fixedly connected to the support plate; A protection assembly matching the second battery cell is installed between the support plate and the base; The lithium - ion battery further includes an ultrasonic detection mechanism for detecting the first battery cell and the second battery cell, and the ultrasonic detection mechanism is used to detect the internal state of the first battery cell and the second battery cell; The protection assembly includes a first box body, in which a connecting plate is slidably connected. The upper end of the connecting plate is fixedly connected to a connecting rod, and one end of the connecting rod penetrates through the top wall of the first box body; A first medium is filled in the first box body, and the first medium is located between the connecting plate and the bottom wall of the first box body; A second box body is installed on one side of the base where the first box body is located. A second medium is filled in the second box body. A first connecting pipe is fixedly connected between the first box body and the second box body. One end of the first connecting pipe is located inside the second box body, and a plurality of second through - holes are opened on the first connecting pipe located in the second box body; A plurality of discharge holes are opened on the support plate, and a second connecting pipe matching the discharge holes is installed between the support plate and the second box body. The first medium and the second medium are mixed in the second box body and then discharged from the discharge holes.

2. The lithium-ion battery according to claim 1, wherein, A convex strip is fixedly connected to the inner wall of the second storage bin, and a plurality of arched protrusions are fixedly connected to the convex strip; 3. A lithium-ion battery according to claim 1, wherein, A second housing is fixedly connected to the first housing, and the controller is located inside the second housing; A first electric connecting wire is installed on the first battery cell, a pole column is installed on the second battery cell, and a second electric connecting wire matching the pole column is installed on the controller. The first electric connecting wire is respectively connected to the controller, and the second battery cell is connected to the controller through the cooperation of the pole column and the second electric connecting wire; 4. A lithium-ion battery according to claim 3, characterized in that, A pulse repair assembly is installed inside the second housing, and the pulse repair assembly realizes the treatment of lithium dendrites in the first battery cell and the second battery cell by means of pulses; 5. A lithium-ion battery according to claim 4, characterized in that, The ultrasonic detection mechanism is installed inside the second housing. The ultrasonic detection mechanism includes an ultrasonic detector. A first detection probe and a second detection probe matching the ultrasonic detector are installed inside the first housing. The first detection probe is used to detect the first battery cell, and the second detection probe is used to detect the second battery cell; 6. A lithium-ion battery according to claim 5, characterized in that, A liquid supplementing mechanism is installed inside the second housing, and the liquid supplementing mechanism is used to supplement repair liquid into the first battery cell or the second battery cell; The liquid replenishing mechanism includes a storage tank, the repair liquid is stored in the storage tank, an infusion tube is installed on the storage tank, and one end of the infusion tube away from the storage tank is fixedly connected with a connector matching the second battery cell; The connector is slidably connected to the second housing, one end of the connector penetrates through the second housing and the first housing, and one end of the connector is located in the second storage bin; A bracket is installed on the second housing, an electromagnet is installed on the bracket, and a magnet matching the electromagnet is fixedly connected to the connector.

7. A lithium-ion battery according to claim 6, characterized in that, The second battery cell includes a first electrode plate and a separator, and a liquid injection tube is arranged between the first electrode plate and the separator; The liquid injection tube includes a third connecting tube and a fourth connecting tube, the fourth connecting tube is slidably connected in the third connecting tube, a first liquid outlet hole and a second liquid outlet hole are respectively formed in the third connecting tube and the fourth connecting tube, and the first liquid outlet hole and the second liquid outlet hole are offset in the up and down directions; A tensioning mechanism matching the fourth connecting tube is installed on the connector.

8. A lithium-ion battery according to claim 7, wherein, A micro battery for supplying power to the electronic components in the second housing is installed in the second housing.

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