A low-temperature resistant lithium supplement cathode material and its preparation method

Abstract

The present invention discloses a low-temperature resistant lithium supplementing cathode material and a preparation method thereof. The low-temperature resistant lithium supplementing cathode material includes a lithium supplementing agent and modified squarylium lithium; wherein, the modified squarylium lithium is prepared by first loading squarylium lithium on graphene activated carbon fiber and then coating a polydopamine layer. The low-temperature resistant lithium supplementing cathode material in the present invention can effectively improve the electrochemical performance of the battery at low temperature and solve the problem of poor performance of the current battery at low temperature.

Description

Technical Field

[0001] The present invention belongs to the technical field of lithium-ion batteries, and particularly relates to a low-temperature resistant lithium supplementing cathode material and a preparation method thereof. Background Art

[0002] In recent years, with the increasing maturity of the development of lithium-ion batteries, their scope of use has become more and more extensive. However, the usage environment of the batteries is relatively complex and changeable, so the performance requirements for lithium-ion batteries are also higher. Among them, people have higher requirements for the charge and discharge performance of lithium-ion batteries in low-temperature environments. When the battery is charged and discharged in a low-temperature environment, the internal resistance of the battery increases, the discharge voltage platform decreases, the charge and discharge capacity decreases, the charge and discharge efficiency of the battery decreases significantly, and the battery itself is damaged to a certain extent. Therefore, how to improve the electrochemical performance of lithium-ion batteries under low-temperature conditions is an urgent problem to be solved. Summary of the Invention

[0003] The purpose of the present invention is to provide a low-temperature resistant lithium supplementing cathode material and a preparation method thereof, and the low-temperature resistant lithium supplementing cathode material can improve the problem of poor performance of current batteries under low temperatures.

[0004] In order to achieve the above purpose, the technical solutions provided by a specific embodiment of the present invention are as follows:

[0005] A low-temperature resistant lithium supplementing cathode material includes a lithium supplementing agent and modified squaric acid lithium;

[0006] Among them, the modified squaric acid lithium is prepared by first loading squaric acid lithium on graphene active carbon fiber and then coating a polydopamine layer.

[0007] In one or more embodiments of the present invention, in the modified squaric acid lithium, the mass ratio of squaric acid lithium to graphene active carbon fiber is 1:(5-10).

[0008] In one or more embodiments of the present invention, the mass of the modified squaric acid lithium is 30-40% of the lithium supplementing agent.

[0009] In one or more embodiments of the present invention, the lithium supplementing agent is selected from lithium manganate, lithium nickel cobalt manganate, lithium cobaltate, lithium iron phosphate, and lithium manganese iron phosphate.

[0010] In one or more embodiments of the present invention, the particle size of the squaric acid lithium is 300-500 nm, the diameter of the graphene active carbon fiber is 3-7 μm, and the length is 1-2 mm.

[0011] In one or more embodiments of the present invention, the preparation of the modified squaric acid lithium is as follows: disperse squaric acid lithium in a solvent, then add graphene active carbon fiber, impregnate under vacuum, and then dry to obtain a squaric acid lithium precursor;

[0012] According to the mass ratio of lithium squarate precursor to dopamine hydrochloride being (15 - 20):1, the lithium squarate precursor is added to the dopamine hydrochloride solution. After the reaction, centrifugation is carried out, the precipitate is taken, and after drying, modified lithium squarate is obtained.

[0013] In one or more embodiments of the present invention, the preparation of the graphene active carbon fiber is as follows: Graphene is dispersed in a solvent to form a slurry, then polytetrafluoroethylene solution is added. After mixing evenly, active carbon fiber is added and ultrasonic treatment is carried out. Then the active carbon fiber is taken out and calcined to obtain graphene active carbon fiber.

[0014] In one or more embodiments of the present invention, the mass ratio of graphene to active carbon fiber is 2:(8 - 10).

[0015] The technical solution provided by another specific embodiment of the present invention is as follows:

[0016] A preparation method of a low-temperature resistant lithium supplementing cathode material, in which a lithium supplementing agent and modified lithium squarate are mixed evenly to obtain the low-temperature resistant lithium supplementing cathode material.

[0017] Compared with the prior art, in the present invention, lithium squarate is first loaded on graphene active carbon fiber, and the low-temperature resistance performance of graphite and active carbon fiber is utilized to ensure the activity of lithium squarate at low temperature, improving the electrochemical performance of the cathode material in a low-temperature environment. Then, a polydopamine layer is coated, which can effectively inhibit the adverse effects of the electrolyte on lithium squarate, so that the battery can maintain stable electrochemical performance at low temperature. Specific Embodiments

[0018] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0019] A specific embodiment of the present invention provides a low-temperature resistant lithium supplementing cathode material, including a lithium supplementing agent and modified lithium squarate, wherein the modified lithium squarate is prepared by first loading lithium squarate on graphene active carbon fiber and then coating a polydopamine layer.

[0020] Specifically, first, carbon fiber in the cathode material can improve the stability and energy density of the battery. Second, carbon fiber has excellent low-temperature resistance and can maintain structural stability in a low-temperature environment. In addition, graphene not only has good low-temperature resistance but also has excellent electrical conductivity, which can improve the charge-discharge efficiency and power performance of the battery. In the present invention, graphene is first compounded with carbon fiber, and then squaric acid lithium is loaded on the high specific surface area of graphene. Finally, a polydopamine layer is coated to inhibit the negative impact of the electrolyte on squaric acid lithium, thereby improving the stability of modified squaric acid lithium at low temperature. At the same time, in combination with a lithium supplement agent, the cycle life of the battery is further improved, and ultimately the purpose of improving the electrochemical performance of the battery in a low-temperature environment is achieved.

[0021] Furthermore, in the modified squaric acid lithium, the mass ratio of squaric acid lithium to graphene active carbon fiber is 1:(5 - 10), the particle size of squaric acid lithium is 300 - 500 nm, the diameter of graphene active carbon fiber is 3 - 7 μm, and the length is 1 - 2 m.

[0022] Specifically, graphene active carbon fiber not only has a high specific surface area but also has abundant pores. In the modified squaric acid lithium, squaric acid lithium is not only filled in the pores of graphene active carbon fiber but also loaded on the surface of graphene active carbon fiber. By controlling the mass ratio and specifications between squaric acid lithium and graphene active carbon fiber, it is beneficial for squaric acid lithium to be loaded both in the pores and on the surface of graphene active carbon fiber, thereby better improving the electrochemical performance of the battery in a low-temperature environment.

[0023] Furthermore, the preparation of modified squaric acid lithium is as follows: First, graphene is dispersed in a solvent to form a slurry, and then a polytetrafluoroethylene solution is added. After mixing evenly, active carbon fiber is added according to the mass ratio of graphene to active carbon fiber of 2:(8 - 10) and ultrasonic treatment is carried out. Then the active carbon fiber is taken out and calcined to obtain graphene active carbon fiber; according to the mass ratio of squaric acid lithium to graphene active carbon fiber of 1:(5 - 10), squaric acid lithium is dispersed in a solvent, and then graphene active carbon fiber is added, and impregnation is carried out under vacuum, and then dried to obtain a squaric acid lithium precursor; according to the mass ratio of squaric acid lithium precursor to dopamine hydrochloride of (15 - 20):1, the squaric acid lithium precursor is added to the dopamine hydrochloride solution, and after reaction, centrifugation is carried out, and the precipitate is taken and dried to obtain modified squaric acid lithium. By controlling the dosage of raw materials, squaric acid lithium can be evenly loaded on graphene active carbon fiber, and at the same time, the polydopamine layer can evenly coat the squaric acid lithium precursor, effectively maintaining the performance of modified squaric acid lithium at low temperature.

[0024] Furthermore, the mass of the modified squaric acid lithium is 30 - 40% of that of the lithium supplement agent.

[0025] Specifically, the lithium supplement is selected from lithium manganate, lithium nickel cobalt manganate, lithium cobaltate, lithium iron phosphate, and lithium manganese iron phosphate. The lithium supplements of the above types all have good cycle stability, stable structure, and high safety, which helps to ensure the stability of the electrochemical performance of the battery at low temperatures.

[0026] Another specific embodiment of the present invention provides a method for preparing a low-temperature resistant lithium-supplemented cathode material, which includes mixing the modified squaric acid lithium and the lithium supplement according to a ratio to obtain the product.

[0027] Specifically, the advantages of using the modified squaric acid lithium to prepare the low-temperature resistant lithium-supplemented cathode material are as follows: The graphene active carbon fiber endows the cathode material with good low-temperature resistance and conductivity. Loading the squaric acid lithium on the graphene active carbon fiber can effectively improve the electrochemical performance of the cathode material at low temperatures; Dopamine hydrochloride can form a polydopamine layer on the squaric acid lithium precursor through self-polymerization. The polydopamine layer can inhibit the negative impact of the electrolyte on the cathode material. At the same time, the polydopamine layer contains microporous structures for lithium ion transmission, which can ensure the effective electrochemical performance of the cathode material.

[0028] The following further elaborates on the present invention with specific examples.

[0029] In the present invention, the graphene is graphene oxide, purchased from Aladdin Chemistry; the polytetrafluoroethylene solution is purchased from Shanghai Fengguang Plastics; the active carbon fiber is purchased from Dongguan Wanlixiang Carbon Fiber.

[0030] Preparation Example of Modified Squaric Acid Lithium

[0031] Preparation Example 1

[0032] Take 10 L of absolute ethanol, add 25 g of graphene and 90 g of sodium bicarbonate to it, and make a slurry by ultrasonic treatment. Under ultrasonic treatment, add 90 g of a 60 wt% polytetrafluoroethylene solution to the slurry, then add 100 g of active carbon fiber with a diameter of 3 - 7 μm and a length of 1 - 2 mm, and ultrasonicate for 1.5 h. After ultrasonication, take out the hollow active carbon fiber and calcine it at 380 °C for 10 min to obtain graphene active carbon fiber.

[0033] According to the mass ratio of squaric acid powder to water of 2:100, dissolve the squaric acid powder in water to make a squaric acid solution. According to the molar ratio of squaric acid (H + ): lithium source (Li + ) of 1:1.15, weigh lithium carbonate, add the lithium carbonate to the squaric acid solution, react at 60 °C for 3.1 h, then vacuum dry at 60 °C, wash with ethanol, and dry to obtain squaric acid lithium. The particle size range of the squaric acid lithium is 300 - 500 nm.

[0034] Take squarylium lithium and graphene active carbon fiber respectively according to the mass ratio of 1:5, disperse squarylium lithium in N-methyl-2-pyrrolidone, then add graphene active carbon fiber, impregnate for 10 min under vacuum environment, and then dry at 80 °C to obtain a squarylium lithium precursor.

[0035] Prepare a tris(hydroxymethyl)aminomethane hydrochloride buffer solution and adjust the pH to 8.5 with hydrochloric acid. Add 60 g of the squarylium lithium precursor and 4 g of dopamine hydrochloride to 1.5 L of the buffer solution and react for 1 h. After the reaction, dry to obtain modified squarylium lithium.

[0036] Preparation Example 2

[0037] Take 10 L of absolute ethanol, add 25 g of graphene and 90 g of sodium bicarbonate to it, and make a slurry after ultrasonic treatment. Under ultrasonic treatment, add 90 g of a 60 wt% polytetrafluoroethylene aqueous solution to the slurry, then add 125 g of hollow active carbon fibers with a diameter of 3 - 7 μm and a length of 1 - 2 mm, and ultrasonicate for 1.5 h. After ultrasonication, take out the hollow active carbon fibers and calcine at 380 °C for 10 min to obtain graphene active carbon fiber.

[0038] According to the mass ratio of squarylium powder to water being 2:100, dissolve squarylium powder in water to make a squarylium solution. According to the molar ratio of squarylium (H + ): lithium source (Li + ) being 1:1.15, weigh lithium carbonate, put lithium carbonate into the squarylium solution, react at 60 °C for 3.1 h, then dry under vacuum at 60 °C, wash with ethanol, and dry to obtain squarylium lithium, and the particle size range of squarylium lithium is 300 - 500 nm.

[0039] Take squarylium lithium and graphene active carbon fiber respectively according to the mass ratio of 1:8, disperse squarylium lithium in N-methyl-2-pyrrolidone, then add graphene active carbon fiber, impregnate for 10 min under vacuum environment, and then dry at 80 °C to obtain a squarylium lithium precursor.

[0040] Prepare a tris(hydroxymethyl)aminomethane hydrochloride buffer solution and adjust the pH to 8.5 with hydrochloric acid. Add 80 g of the squarylium lithium precursor and 4 g of dopamine hydrochloride to 1.5 L of the buffer solution and react for 1 h. After the reaction, dry to obtain modified squarylium lithium.

[0041] Preparation Example 3

[0042] Take 10 L of anhydrous ethanol, add 25 g of graphene and 90 g of sodium bicarbonate thereto, and make a slurry after ultrasonic treatment. Under ultrasonic treatment, add 90 g of an aqueous polytetrafluoroethylene solution with a concentration of 60 wt% to the slurry, then add 100 g of hollow activated carbon fibers with a diameter of 3 - 7 μm and a length of 1 - 2 mm, and perform ultrasonic treatment for 1.5 h. After ultrasonic treatment, take out the hollow activated carbon fibers and calcine them at 380 °C for 10 min to obtain graphene-activated carbon fibers.

[0043] According to the mass ratio of squaric acid powder to water being 2:100, dissolve the squaric acid powder in water to make a squaric acid solution. According to the molar ratio of squaric acid (H + ): lithium source (Li + ) being 1:1.15, weigh lithium carbonate, put the lithium carbonate into the squaric acid solution, react at 60 °C for 3.1 h, then perform vacuum drying at 60 °C, wash with ethanol, and dry to obtain lithium squarate. The particle size range of lithium squarate is 300 - 500 nm.

[0044] Take lithium squarate and graphene-activated carbon fibers according to the mass ratio of lithium squarate to graphene-activated carbon fibers being 1:10. Disperse the lithium squarate in N-methyl-2-pyrrolidone, then add the graphene-activated carbon fibers, impregnate in a vacuum environment for 10 min, and then dry at 80 °C to obtain a lithium squarate precursor.

[0045] Prepare a tris(hydroxymethyl)aminomethane hydrochloride buffer solution and adjust the pH to 8.5 with hydrochloric acid. Add 68 g of the lithium squarate precursor and 4 g of dopamine hydrochloride to 1.5 L of the buffer solution and react for 1 h. After the reaction, dry to obtain modified lithium squarate.

[0046] Preparation Example 4

[0047] The difference between this preparation example and Preparation Example 1 is only that the mass ratio of lithium squarate to graphene-activated carbon fibers is 1:20.

[0048] Preparation Example 5

[0049] The difference between this preparation example and Preparation Example 1 is only that prepare a tris(hydroxymethyl)aminomethane hydrochloride buffer solution and adjust the pH to 8.5 with hydrochloric acid. Add 100 g of the lithium squarate precursor and 4 g of dopamine hydrochloride to 1.5 L of the buffer solution and react for 1 h. After the reaction, dry to obtain modified lithium squarate.

[0050] Examples of Low-Temperature Lithium-Supplementing Cathode Materials

[0051] Example 1

[0052] Take the modified lithium squarate and lithium manganate in Preparation Example 1, mix the two according to the mass of the modified lithium squarate being 30% of the mass of the lithium manganate, and stir at a speed of 600 r / min for 30 min to obtain a low-temperature lithium-supplementing cathode material.

[0053] Example 2

[0054] Take the modified squarylium lithium and lithium manganate in Preparation Example 1, mix the two according to the mass of the modified squarylium lithium being 36% of the mass of the lithium manganate, and stir at a speed of 600 r / min for 30 min to obtain a low-temperature resistant lithium-supplemented cathode material.

[0055] Example 3

[0056] Take the modified squarylium lithium and lithium manganate in Preparation Example 1, mix the two according to the mass of the modified squarylium lithium being 40% of the mass of the lithium manganate, and stir at a speed of 600 r / min for 30 min to obtain a low-temperature resistant lithium-supplemented cathode material.

[0057] Example 4

[0058] Take the modified squarylium lithium and lithium manganate in Preparation Example 2, mix the two according to the mass of the modified squarylium lithium being 30% of the mass of the lithium manganate, and stir at a speed of 600 r / min for 30 min to obtain a low-temperature resistant lithium-supplemented cathode material.

[0059] Example 5

[0060] Take the modified squarylium lithium and lithium manganate in Preparation Example 3, mix the two according to the mass of the modified squarylium lithium being 30% of the mass of the lithium manganate, and stir at a speed of 600 r / min for 30 min to obtain a low-temperature resistant lithium-supplemented cathode material.

[0061] Example 6

[0062] Take the modified squarylium lithium and lithium manganate in Preparation Example 4, mix the two according to the mass of the modified squarylium lithium being 30% of the mass of the lithium manganate, and stir at a speed of 600 r / min for 30 min to obtain a low-temperature resistant lithium-supplemented cathode material.

[0063] Example 7

[0064] Take the modified squarylium lithium and lithium manganate in Preparation Example 5, mix the two according to the mass of the modified squarylium lithium being 30% of the mass of the lithium manganate, and stir at a speed of 600 r / min for 30 min to obtain a low-temperature resistant lithium-supplemented cathode material.

[0065] Comparative Example 1

[0066] Take 10 L of absolute ethanol, add 25 g of graphene and 90 g of sodium bicarbonate thereto, and make a slurry by ultrasonic treatment. Under ultrasonic treatment, add 90 g of a 60 wt% aqueous solution of polytetrafluoroethylene to the slurry, then add 100 g of activated carbon fiber, and ultrasonic for 1.5 h. After ultrasonic treatment, take out the activated carbon fiber and calcine it at 380 °C for 10 min to obtain graphene-activated carbon fiber.

[0067] According to the mass ratio of squaric acid powder to water being 2:100, dissolve the squaric acid powder in water to make a squaric acid solution. According to squaric acid (H+ ): The molar ratio of the lithium source (Li + ): is 1:1.15. Lithium carbonate was weighed and put into the squaric acid solution, reacted at 60 °C for 3.1 h, then dried in vacuum at 60 °C, washed with ethanol, and dried to obtain lithium squarate.

[0068] The three were mixed according to the mass of lithium squarate being 5% of the mass of lithium manganate and the mass of graphene activated carbon fiber being 25% of the mass of lithium manganate, and stirred at a speed of 600 r / min for 30 min to obtain the lithium-supplemented cathode material.

[0069] Comparative Example 2

[0070] Take 10 L of absolute ethanol, add 25 g of graphene and 90 g of sodium bicarbonate to it, and make a slurry by ultrasonic treatment. Under ultrasonic treatment, 90 g of an aqueous solution of polytetrafluoroethylene with a concentration of 60 wt% was added to the slurry, and then 100 g of activated carbon fiber was added, and ultrasonic treatment was carried out for 1.5 h. After ultrasonic treatment, the activated carbon fiber was taken out and calcined at 380 °C for 10 min to obtain graphene activated carbon fiber.

[0071] According to the mass ratio of squaric acid powder to water being 2:100, the squaric acid powder was dissolved in water to make a squaric acid solution. According to the molar ratio of squaric acid (H + ): the lithium source (Li + ): is 1:1.15. Lithium carbonate was weighed and put into the squaric acid solution, reacted at 60 °C for 3.1 h, then dried in vacuum at 60 °C, washed with ethanol, and dried to obtain lithium squarate.

[0072] Lithium squarate and graphene activated carbon fiber were taken respectively according to the mass ratio of lithium squarate to graphene activated carbon fiber being 1:5. Lithium squarate was dispersed in N-methyl-2-pyrrolidone, and then graphene activated carbon fiber was added, impregnated in a vacuum environment for 10 min, and then dried at 80 °C to obtain modified lithium squarate.

[0073] The two were mixed according to the mass of modified lithium squarate being 30% of the mass of lithium manganate, and stirred at a speed of 600 r / min for 30 min to obtain the lithium-supplemented cathode material.

[0074] Performance tests were carried out on the lithium-supplemented cathode materials in each example and each comparative example, as follows:

[0075] The lithium - supplemented cathode material, conductive carbon black, and PVDF were added to N - methyl - 2 - pyrrolidone in a mass ratio of 8:1:1, mixed evenly to form a slurry. The slurry was evenly coated on aluminum foil and dried in an 80°C oven to obtain the positive electrode sheet. The positive electrode sheet was assembled into a button battery, the electrolyte was 1 mol / L LiPF6 (EC:DMC = 1:1), and the negative electrode used a lithium sheet. The battery was charged at a current of 0.5C at room temperature. After 5 minutes, it was discharged at 0.2C to 2.5V, and the capacity was recorded and denoted as Capacity 1. After the battery was charged again at 0.5C, the battery was placed at - 20°C and - 30°C respectively, and then started to discharge at a current of 0.2C. The capacity at - 20°C was denoted as Capacity 2, and the capacity at - 30°C was denoted as Capacity 3. The capacity retention rate of the battery at - 20°C was Capacity 2 / Capacity 1×100%, and the capacity retention rate of the battery at - 30°C was Capacity 3 / Capacity 1×100%.

[0076] Table 1 Electrochemical Test Results

[0077]

[0078] Compared with Comparative Example 1 and Comparative Example 2, the low - temperature lithium - supplemented cathode material in the examples of the present invention has a higher low - temperature discharge capacity retention rate, showing better low - temperature performance. It indicates that by first loading lithium squarate on graphene activated carbon fiber and then coating polydopamine in the present invention, the electrochemical performance of the battery at low temperature can be effectively improved.

[0079] In addition, comparing Example 1, Example 6, and Example 7, the low - temperature discharge capacity retention rates of the low - temperature lithium - supplemented cathode materials in Example 6 and Example 7 are slightly lower than that in Example 1. This shows that preparing the low - temperature lithium - supplemented cathode material according to the ratio disclosed in this application can ensure that the low - temperature lithium - supplemented cathode material has excellent electrochemical performance and meets the performance requirements of the battery at low temperature.

[0080] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above - mentioned exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non - restrictive. 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 encompassed within the present invention. In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way 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 low temperature resistant lithium supplementing positive electrode material, characterized in that: Including lithium supplements and modified lithium squarate; Wherein, the modified lithium squarate is prepared by first loading lithium squarate on graphene activated carbon fiber and then coating it with a polydopamine layer; The modified lithium squarate is prepared by dispersing lithium squarate in a solvent, adding graphene activated carbon fiber, impregnating under vacuum, and then drying to obtain a lithium squarate precursor; According to the mass ratio of the lithium squarate precursor to dopamine hydrochloride of (15-20): 1, the lithium squarate precursor is added to the dopamine hydrochloride solution, centrifuged after the reaction, and the precipitate is taken and dried to obtain the modified lithium squarate; The graphene activated carbon fiber is prepared by dispersing graphene in a solvent to prepare a slurry, adding a polytetrafluoroethylene solution, mixing well, adding activated carbon fiber and performing ultrasonic treatment, then taking out the activated carbon fiber and calcining it to obtain the graphene activated carbon fiber; The particle size of the lithium squarate is 300-500nm, the diameter of the graphene activated carbon fiber is 3-7μm, and the length is 1-2mm; In the modified lithium squarate, the mass ratio of lithium squarate to graphene activated carbon fiber is 1:(5-10).

2. The low temperature resistant lithium supplementing positive electrode material according to claim 1, characterized in that: The mass of the modified lithium squarate is 30-40% of the lithium supplement agent.

3. The low temperature resistant lithium supplementing positive electrode material according to claim 1, characterized in that: The lithium supplement is selected from lithium manganese oxide, lithium nickel cobalt manganese oxide, lithium cobalt oxide, lithium iron phosphate and lithium manganese iron phosphate.

4. The low temperature resistant lithium supplementing positive electrode material according to claim 1, characterized in that: The mass ratio of the graphene to the activated carbon fiber is 2:(8-10).

5. The method for preparing the low temperature resistant lithium supplementing positive electrode material according to any one of claims 1 to 4, characterized in that: The lithium replenishing agent and the modified lithium squarate are mixed evenly to obtain a low-temperature resistant lithium replenishing positive electrode material.

Images