Battery, battery pack and electric equipment

Abstract

The invention discloses a battery, a battery pack and electric equipment, and the battery comprises a positive electrode active material and 1, 1-diphenyl-2-trinitrophenylhydrazine. According to the battery disclosed by the invention, 1, 1-diphenyl-2-trinitrophenylhydrazine is used as a free radical trapping agent to capture active oxygen and metal ions released by the positive electrode active material, so that the side reaction of an electrolyte is inhibited, the gas production rate of the battery is reduced, and the cycle performance of the battery is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery, a battery pack and an electrical device. Background Art

[0002] In related technologies, at higher voltages (>4.5V vs. Li+ / Li), phase transitions are prone to occur in the positive electrode active material, such as the lithium-rich phase. Lattice oxygen participates in electrochemical reactions to release reactive oxygen and dissolve metal ions. Reactive oxygen and metal ions easily catalyze the decomposition of the electrolyte, resulting in poor battery cycle performance, capacity decay, and reduced safety. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the first object of the present invention is to provide a battery in which 1,1-diphenyl-2-trinitrophenylhydrazine captures reactive oxygen and metal ions released by the positive electrode active material, inhibits electrolyte side reactions, reduces battery gas production, and improves battery cycle performance.

[0004] A second object of the present invention is to provide a battery pack.

[0005] The third object of the present invention is to provide an electrical device.

[0006] A battery according to an embodiment of the first aspect of the present invention includes: a positive electrode active material and 1,1-diphenyl-2-trinitrophenylhydrazine material.

[0007] According to the battery of an embodiment of the present invention, 1,1-diphenyl-2-trinitrophenylhydrazine acts as a free radical scavenger to capture active oxygen and metal ions released by the positive electrode active material, inhibiting side reactions of the electrolyte, reducing battery gas production, and improving the battery's cycle performance.

[0008] According to some embodiments of the present invention, a weight ratio of the 1,1-diphenyl-2-trinitrophenylhydrazine to the positive electrode active material is w, and the w satisfies: 0.1%≤w≤20%.

[0009] According to some embodiments of the present invention, the positive electrode active material includes positive electrode active material particles, at least a portion of the positive electrode active material particles are provided with a coating layer, and the coating layer includes 1,1-diphenyl-2-trinitrophenylhydrazine.

[0010] According to some embodiments of the present invention, the thickness of the coating layer is d, wherein d satisfies: 0.2um≤d≤5um.

[0011] According to some embodiments of the present invention, the positive electrode active material includes a layered oxide positive electrode active material and / or a phosphate-based positive electrode active material.

[0012] According to some embodiments of the present invention, the positive electrode active material includes a lithium-rich manganese-based material.

[0013] According to some embodiments of the present invention, the positive electrode active material further includes lithium manganese iron phosphate material.

[0014] According to some embodiments of the present invention, the weight ratio of the lithium iron manganese phosphate material to the lithium-rich manganese-based material satisfies (85-90): (10-15).

[0015] According to some embodiments of the present invention, the positive electrode active material further includes lithium cobaltate and / or LiNixCoyMnzO2 (x>0, y>0, z>0, x+y+z=1).

[0016] According to some embodiments of the present invention, the weight percentage of the lithium cobalt oxide and LiNixCoyMnzO2 to the weight percentage of the positive electrode active material is 1% to 99%, preferably 80% to 99%.

[0017] According to some embodiments of the present invention, the battery includes a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode, the positive electrode includes the positive electrode active material, and at least one of the positive electrode, the negative electrode, and the separator includes the 1,1-diphenyl-2-trinitrophenylhydrazine.

[0018] According to some embodiments of the present invention, the positive electrode includes a positive electrode current collector and a positive electrode material supported on the positive electrode current collector, and the positive electrode material includes the positive electrode active material and 1,1-diphenyl-2-trinitrophenylhydrazine.

[0019] According to some embodiments of the present invention, the separator is coated with 1,1-diphenyl-2-trinitrophenylhydrazine, and the weight percentage of the 1,1-diphenyl-2-trinitrophenylhydrazine in the positive electrode active material of the battery is: 0.1% to 20%.

[0020] According to some embodiments of the present invention, the battery further includes an electrolyte containing the 1,1-diphenyl-2-trinitrophenylhydrazine.

[0021] A battery pack according to an embodiment of the second aspect of the present invention includes at least one battery according to an embodiment of the first aspect of the present invention.

[0022] An electric device according to an embodiment of a third aspect of the present invention comprises at least one battery pack according to an embodiment of the second aspect of the present invention.

[0023] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments with reference to the following drawings, in which: Figure 1 is a schematic diagram of a positive electrode material according to an embodiment of the present invention.

[0025] Reference numerals: 100: positive electrode active material; 1: positive electrode active material particles; 2: coating layer. DETAILED DESCRIPTION

[0026] Reference below Figure 1 A battery according to an embodiment of the first aspect of the present invention is described.

[0027] like Figure 1 As shown, the battery according to the first embodiment of the present invention includes a positive electrode active material 100 and 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH).

[0028] The structural formula of 1,1-diphenyl-2-trinitrophenylhydrazine is as follows: .

[0029] Among them, 1,1-diphenyl-2-trinitrophenylhydrazine is a dark purple crystalline powder. It is a very stable nitrogen-centered free radical that can capture other free radicals and can exist stably. Its molecular formula is C 18 H 12 N5O6, molecular weight is 394.32, purity is >98%, melting point is around 130℃.

[0030] 1,1-Diphenyl-2-trinitrophenylhydrazine acts as a free radical scavenger to capture oxygen free radicals and metal ions generated by the positive electrode active material 100 during operation, thereby enabling the battery to have excellent electrochemical properties, thereby improving battery cycle performance, ensuring battery capacity, and enhancing battery safety.

[0031] 1,1-Diphenyl-2-trinitrophenylhydrazine has excellent chemical and thermal stability, maintaining its activity at relatively high temperatures (below 150°C). This improves its ability to capture oxygen free radicals and metal ions in the positive electrode active material 100 during battery operation. Furthermore, 1,1-Diphenyl-2-trinitrophenylhydrazine is relatively low in toxicity, which helps reduce the battery's environmental impact.

[0032] According to the battery of the embodiment of the present invention, 1,1-diphenyl-2-trinitrophenylhydrazine acts as a free radical scavenger to capture active oxygen and metal ions released by the positive electrode active material 100, inhibiting electrolyte side reactions, reducing battery gas production, and improving battery cycle performance.

[0033] The weight ratio of 1,1-diphenyl-2-trinitrophenylhydrazine to the positive electrode active material 100 is w, where w satisfies the following conditions: 0.1% ≤ w ≤ 20%. Thus, by setting the weight ratio of 1,1-diphenyl-2-trinitrophenylhydrazine to the positive electrode active material 100 within 0.1% ≤ w ≤ 20%, the weight ratio of 1,1-diphenyl-2-trinitrophenylhydrazine to the positive electrode active material 100 is set more reasonably. 1,1-diphenyl-2-trinitrophenylhydrazine can fully capture oxygen free radicals and metal ions in the positive electrode active material 100, while avoiding waste of 1,1-diphenyl-2-trinitrophenylhydrazine and facilitating guaranteed battery capacity.

[0034] According to some embodiments of the present invention, a positive electrode active material 100 includes positive electrode active material particles 1, at least some of which are coated with a coating layer 2 comprising 1,1-diphenyl-2-trinitrophenylhydrazine. This configuration allows for a uniform distribution of DPPH within the positive electrode active material 100, allowing the 1,1-diphenyl-2-trinitrophenylhydrazine to efficiently capture reactive oxygen species and metal ions generated by the positive electrode active material particles 1, preventing these reactive oxygen species and metal ions from reacting with the electrolyte, thereby improving the electrolyte's operational stability and enhancing the battery's electrochemical performance.

[0035] Furthermore, the thickness of the coating layer 2 is d, where d satisfies: 0.2 μm ≤ d ≤ 10 μm. Thus, by setting the thickness of the coating layer 2 to 0.2 μm ≤ d ≤ 10 μm, the thickness of the coating layer 2 is set more reasonably. On the one hand, it is beneficial for 1,1-diphenyl-2-trinitrophenylhydrazine to fully capture oxygen free radicals and metal ions in the positive electrode active material 100. On the other hand, it avoids the coating layer 2 being too thick, which may result in lithium ions in the positive electrode active material 100 not being able to quickly contact the electrolyte, and avoids the waste of 1,1-diphenyl-2-trinitrophenylhydrazine, which is beneficial to ensuring the capacity of the battery.

[0036] According to some embodiments of the present invention, the positive electrode active material 100 includes a layered oxide positive electrode active material and / or a phosphate-based positive electrode active material. The layered oxide positive electrode active material has a layered crystal structure. For example, the layered oxide positive electrode active material includes one or more of a lithium-rich manganese-based material, lithium cobalt oxide, and LiNixCoyMnzO2. Phosphate-based positive electrode active materials include lithium iron manganese phosphate, lithium iron phosphate, and the like. Phosphate-based positive electrode active materials have good thermal and structural stability, allowing them to remain relatively safe even under overcharge or high-temperature conditions.

[0037] According to some other embodiments of the present invention, the positive electrode active material 100 includes a lithium-rich manganese-based material. Lithium-rich manganese-based materials generally refer to layered oxide materials with a high lithium content, and the chemical formula can be expressed as xLi2MnO3·(1-x)LiTMO2, where TM represents one or more transition metals such as nickel (Ni), manganese (Mn), and cobalt (Co). This type of material is regarded as one of the important candidates for the next generation of lithium-ion battery positive electrode materials because of its extremely high theoretical specific capacity (over 350mAh / g) and reversible specific capacity (greater than 250mAh / g). Advantages include high capacity: The high specific capacity of lithium-rich manganese-based materials is due to their unique anion redox reaction (O2⁻ / O － / O2) and transition metal ions (such as Ni 2＋ / Ni 4＋ ,Co 3＋ / Co 4＋ , Mn 3＋ / Mn 4＋ ) redox couple, which theoretically allows it to store more lithium ions, thereby increasing the battery's energy density. Low cost: Reducing the use of cobalt and nickel reduces material costs. Meanwhile, the relatively abundant manganese resources facilitate large-scale commercial production.

[0038] Among them, because lithium-rich manganese-based materials release reactive oxygen and / or dissolve metal ions during the charge and discharge process, the phase change process of lithium-rich manganese-based materials releases reactive oxygen, which accelerates the catalytic oxidation of the electrolyte, increases side reactions in the battery, sharply increases impedance, and leads to severe degradation of battery performance. The free radical scavenger 1,1-diphenyl-2-trinitrophenylhydrazine can capture the reactive oxygen and metal ions released by lithium-rich manganese-based materials, inhibiting electrolyte side reactions, reducing battery gas production, and improving battery cycle performance.

[0039] According to some embodiments of the present invention, the positive electrode active material 100 further comprises a lithium iron manganese phosphate material. The lithium iron manganese phosphate material has excellent thermal and chemical stability, performs well in both high and low temperature environments, and has a high energy density and a high operating voltage. Therefore, using the lithium iron manganese phosphate material as the positive electrode active material 100 is beneficial for improving the energy output of the battery.

[0040] Among them, lithium manganese iron phosphate (LiMnFePO4, abbreviated as LMFP) is obtained by doping conventional lithium iron phosphate (LiFePO4, abbreviated as LFP) with a certain proportion of manganese. This material combines the safety and long cycle life of lithium iron phosphate with the high voltage platform advantage brought by manganese, demonstrating higher energy density than lithium iron phosphate. Key features and advantages include: High energy density. Due to the manganese doping, the voltage platform of lithium manganese iron phosphate can be increased from approximately 3.4V of LFP to 3.8-4.1V. This directly leads to a theoretical energy density that is 10%-20% higher than LFP, approaching or sometimes even exceeding the level of some ternary materials. Safety. LMFP maintains the olivine structure similar to LFP. This structural stability makes it less susceptible to structural failure even under extreme conditions (such as overcharge and high temperature), thus ensuring battery safety and surpassing layered ternary materials. Cost-effectiveness. Avoiding the use of expensive nickel and cobalt reduces dependence on rare metals, resulting in significant cost advantages. LMFP is also compatible with LFP production lines, making it easy to industrialize. Under low temperature conditions, LMFP exhibits better capacity retention than LFP.

[0041] During the charge and discharge process of lithium manganese iron phosphate materials, a large impedance will be formed at the iron-manganese platform switching point and the end of the manganese platform, which will increase polarization and cause battery performance to decay. After the lithium manganese iron phosphate material is mixed with the lithium-rich manganese-based material, the interaction between the lithium manganese iron phosphate material and the lithium-rich manganese-based material can play a role in the stage from the end of the iron platform to the early stage of the manganese platform and the end of the manganese platform, thereby improving the battery cycle performance. The manganese platform of the lithium manganese iron phosphate material operates at around 4.1V (vs. Li+ / Li), and the working potential of the lithium-rich manganese-based material is also in the high voltage area. After the lithium manganese iron phosphate material is mixed with the lithium-rich manganese-based material, it can not only increase the specific capacity of the positive electrode active material 100, but also increase the operating voltage of the battery, thereby increasing the energy density of the battery.

[0042] According to some embodiments of the present invention, the weight ratio of the lithium iron manganese phosphate material to the lithium-rich manganese-based material satisfies (85-90):(10-15). Thus, the weight ratio of the lithium iron manganese phosphate material to the lithium-rich manganese-based material is reasonable, allowing the lithium iron manganese phosphate material and the lithium-rich manganese-based material to fully exert their interaction, thereby improving the battery's cycle performance and energy density.

[0043] According to some specific embodiments of the present invention, the positive electrode active material 100 also includes lithium cobalt oxide and / or LiNixCoyMnzO2 (xyz>0, x+y+z=1). Among them, lithium cobalt oxide has the advantages of high operating voltage, stable discharge, high specific energy and good cycle performance. LiNixCoyMnzO2 has a high energy density, and the addition of Mn can also improve the structural stability and safety of the positive electrode material. The Co element helps to improve the cycle stability and rate performance of the material, while Mn can enhance the structural stability and thermal stability of the positive electrode active material 100, reduce capacity attenuation at high temperatures, and improve the safety of the positive electrode active material 100.

[0044] The weight percentage of lithium cobalt oxide and LiNixCoyMnzO2 in the positive electrode active material 100 is 1% to 99%. This helps reduce the amount of lithium manganese-based materials used, thereby optimizing the components and ratio of the positive electrode active material 100, improving the performance of the positive electrode active material 100, and reducing the cost of the positive electrode active material 100.

[0045] Preferably, the weight percentage of lithium cobalt oxide and LiNixCoyMnzO2 to the weight percentage of the positive electrode active material 100 is 80% to 99%.

[0046] According to some embodiments of the present invention, a battery includes a positive electrode, a negative electrode, and a separator disposed between the positive and negative electrodes. The positive electrode includes a positive electrode active material 100, and at least one of the positive electrode, the negative electrode, and the separator includes 1,1-diphenyl-2-trinitrophenylhydrazine. The addition of 1,1-diphenyl-2-trinitrophenylhydrazine to at least one of the positive electrode, the negative electrode, and the separator facilitates the utilization of 1,1-diphenyl-2-trinitrophenylhydrazine, namely, 1,1-diphenyl-2-trinitrophenylhydrazine captures reactive oxygen species and metal ions released by the positive electrode active material 100, inhibits electrolyte side reactions, reduces battery gas production, and improves battery cycle performance.

[0047] Furthermore, the positive electrode includes a positive electrode current collector and a positive electrode material supported by the positive electrode current collector. The positive electrode material includes a positive electrode active material 100 and 1,1-diphenyl-2-trinitrophenylhydrazine. The function of the positive electrode current collector is to provide an electron conduction path and serve as a support material to support the positive electrode material. The positive electrode current collector can collect electrons transmitted from the positive electrode material and guide them to the external circuit of the battery. Including 1,1-diphenyl-2-trinitrophenylhydrazine in the positive electrode material can reduce the flow path of active oxygen and metal ions released by the positive electrode active material 100, allowing them to be quickly captured by 1,1-diphenyl-2-trinitrophenylhydrazine, further reducing battery gas production and improving battery cycle performance. In some embodiments, all 1,1-diphenyl-2-trinitrophenylhydrazine in the battery is added to the positive electrode as part of the positive electrode material.

[0048] According to some specific embodiments of the present invention, the separator is coated with 1,1-diphenyl-2-trinitrophenylhydrazine, and the weight percentage of 1,1-diphenyl-2-trinitrophenylhydrazine in the positive electrode active material 100 in the battery is: 0.1% to 20%. Therefore, including 0.1% to 20% by weight of 1,1-diphenyl-2-trinitrophenylhydrazine in the battery separator is beneficial for improving the battery's cycling performance and electrochemical performance. By setting the weight percentage of 1,1-diphenyl-2-trinitrophenylhydrazine in the positive electrode material to 0.1% to 20%, it is beneficial to fully capture active oxygen and metal ions in the electrolyte or separator, inhibit side reactions in the electrolyte or separator, reduce battery gas production, and improve battery cycling performance. At the same time, it avoids excessive thickness of the separator caused by excessive addition of 1,1-diphenyl-2-trinitrophenylhydrazine.

[0049] The battery also includes an electrolyte containing 1,1-diphenyl-2-trinitrophenylhydrazine. The 1,1-diphenyl-2-trinitrophenylhydrazine in the electrolyte can capture active oxygen and metal ions in the cathode material, improving the battery's cycle performance and safety.

[0050] For example, a method for preparing the positive electrode material 100 includes the following steps: The positive electrode active material 100 and 1,1-diphenyl-2-trinitrophenylhydrazine are premixed to obtain the product.

[0051] According to the preparation method of the positive electrode material 100 of an embodiment of the present invention, by premixing the positive electrode active material particles 1 and 1,1-diphenyl-2-trinitrophenylhydrazine, it is beneficial to improve the distribution uniformity of 1,1-diphenyl-2-trinitrophenylhydrazine and the positive electrode active material particles 1, thereby improving the balance consistency of the positive electrode material 100.

[0052] Furthermore, premixing includes adding the positive electrode active material particles 1 to 1,1-diphenyl-2-trinitrophenylhydrazine, or adding 1,1-diphenyl-2-trinitrophenylhydrazine to the positive electrode active material particles 1. Therefore, in the actual preparation process, the order of adding the positive electrode active material particles 1 and 1,1-diphenyl-2-trinitrophenylhydrazine can be adjusted as needed, facilitating the production of the positive electrode material 100.

[0053] A battery pack according to an embodiment of the second aspect of the present invention includes at least one battery according to an embodiment of the first aspect of the present invention.

[0054] The battery pack according to the embodiment of the present invention is conducive to improving the performance of the battery pack, reducing the gas production of the battery pack, and improving the stability and safety of the battery pack. The battery pack can refer to a battery module, a battery pack, etc.

[0055] According to an embodiment of the third aspect of the present invention, an electric device includes at least one battery pack according to an embodiment of the second aspect of the present invention. The electric device may be a vehicle, a mobile electronic device, an energy storage system, or the like.

[0056] The electric device according to the embodiment of the present invention is conducive to improving the operational stability of the electric device, enhancing the user experience, and improving the market competitiveness of the electric device.

[0057] The following embodiments of the present invention are described in detail. It should be noted that the following embodiments are illustrative and are intended only to explain the present invention and are not to be construed as limiting the present invention. In addition, unless otherwise expressly stated, all reagents used in the following embodiments are commercially available or can be synthesized according to methods described herein or known methods. Reaction conditions not listed are also readily available to those skilled in the art.

[0058] Example 1 The preparation / composition of the positive electrode, negative electrode, separator and electrolyte are as follows: Positive electrode: The positive electrode active material 100 (the positive electrode active material 100 includes LMFP and LLOS with a mass ratio of 85:15, and the specific chemical formula of LLOS is Li 1.153 Ni 0.259 Co 0.054 Mn 0.533 O2), conductive agent Ketjen black, binder polyvinylidene fluoride (PVDF), and free radical scavenger DPPH are fully stirred and mixed in N-methylpyrrolidone (NMP) solvent in a mass ratio of 96:2:2:5, and then coated on both sides of the positive electrode current collector aluminum foil. After drying and roller pressing, the positive electrode is obtained.

[0059] Negative electrode: Graphite, SP conductive carbon black, sodium carboxymethyl cellulose (CMC-Na), styrene-butadiene rubber (SBR), and binder polyacrylic acid (PAA) are mixed and dispersed in a solvent (a mixed solvent of N-methylpyrrolidone and water) in a mass ratio of 100:1:0.7:0.8:1.5, and then coated on both sides on the negative electrode current collector copper foil. After drying and rolling, the negative electrode is obtained.

[0060] Isolator: Made of polyethylene (PE) ceramic film.

[0061] Electrolyte: The lithium salt is lithium hexafluorophosphate LiPF6, and the organic solvents include ethylene carbonate (EC), ethyl methyl carbonate (EMC) and dimethyl carbonate (DMC).

[0062] Examples 2-8 The batteries of Examples 2-8 are substantially the same as Example 1, except that the relative contents of LMFP, LLOS, or DPPH are changed. See Table 1 for details.

[0063] Example 9 The difference between Example 9 and Example 1 is that a free radical scavenger DPPH is added to the negative electrode, and the amount of DPPH added accounts for 5% of the positive electrode active material 100. Specifically, the preparation / composition of the positive electrode, negative electrode, separator and electrolyte are as follows: Positive electrode: The positive electrode active material 100 (the positive electrode active material 100 includes LMFP and LLOS in a mass ratio of 85:15), the conductive agent Ketjen black, and the binder polyvinylidene fluoride (PVDF) in a mass ratio of 96:2:2 are thoroughly stirred and mixed in N-methylpyrrolidone (NMP) solvent, and then coated on both sides of the positive electrode current collector aluminum foil. After drying and roll pressing, the positive electrode is obtained.

[0064] Negative electrode: Graphite, SP conductive carbon black, sodium carboxymethyl cellulose (CMC-Na), styrene-butadiene rubber (SBR), binder polyacrylic acid (PAA), and DPPH were mixed and dispersed in a solvent (a mixture of N-methylpyrrolidone and water). The mixture was then coated on both sides of a copper foil negative electrode current collector. After drying and roll-pressing, the negative electrode was obtained. The mass ratio of graphite, SP conductive carbon black, sodium carboxymethyl cellulose (CMC-Na), styrene-butadiene rubber (SBR), and binder polyacrylic acid (PAA) was 100:1:0.7:0.8:1.5. The amount of DPPH added accounted for 5% of the total positive electrode active material.

[0065] Isolator: Made of polyethylene (PE) ceramic film.

[0066] Electrolyte: The lithium salt is lithium hexafluorophosphate LiPF6, and the organic solvents include ethylene carbonate (EC), ethyl methyl carbonate (EMC) and dimethyl carbonate (DMC).

[0067] Example 10 Example 10 is substantially the same as Example 1, except that the separator is coated with a radical scavenger DPPH, which accounts for 5% of the weight of the positive electrode active material 100 in the battery. The amount of DPPH accounts for 5% of the positive electrode active material 100. Specifically, the preparation / composition of the positive electrode, negative electrode, separator, and electrolyte are as follows: Positive electrode: The positive electrode active material 100 (the positive electrode active material 100 includes LMFP and LLOS in a mass ratio of 85:15), the conductive agent Ketjen black, and the binder polyvinylidene fluoride (PVDF) in a mass ratio of 96:2:2 are thoroughly stirred and mixed in N-methylpyrrolidone (NMP) solvent, and then coated on both sides of the positive electrode current collector aluminum foil. After drying and roll pressing, the positive electrode is obtained.

[0068] Negative electrode: Graphite, SP conductive carbon black, sodium carboxymethyl cellulose (CMC-Na), styrene-butadiene rubber (SBR), and binder polyacrylic acid (PAA) are mixed and dispersed in a solvent (a mixed solvent of N-methylpyrrolidone and water) in a mass ratio of 100:1:0.7:0.8:1.5, and then coated on both sides on the negative electrode current collector copper foil. After drying and rolling, the negative electrode is obtained.

[0069] Separator: A polyethylene (PE) ceramic film is used, and DPPH is coated on the polyethylene (PE) ceramic film, and the amount of DPPH accounts for 5% of 100% of the positive electrode active material.

[0070] Electrolyte: The lithium salt is lithium hexafluorophosphate LiPF6, and the organic solvents include ethylene carbonate (EC), ethyl methyl carbonate (EMC) and dimethyl carbonate (DMC).

[0071] Comparative Example 1 Comparative Example 1 differs from Example 1 only in that DPPH is not included.

[0072] Table 1 Component ratios of Examples 1 to 10 and Comparative Example 1

[0073] Examples 1-10 present different experimental groups with the addition of the free radical scavenger 1,1-diphenyl-2-trinitrophenylhydrazine. Comparative Example 1 presents a blank control experiment without the addition of 1,1-diphenyl-2-trinitrophenylhydrazine. The positive electrodes from the experimental and comparative groups were fabricated into batteries using the standard battery preparation process, along with graphite negative electrode sheets, separators, and electrolytes. The batteries were designed to have a capacity of 700 mAh and electrochemical testing was performed in a battery testing cabinet.

[0074] Battery initial efficiency and gas production test Perform the first charge and discharge test on the battery using a Blue Electric test cabinet. Charge at 0.1C to a cutoff voltage of 4.55V (0.02C cutoff current), and record the initial charge capacity. Discharge at 0.1C to a cutoff voltage of 2.5V (0.02C cutoff current), and record the initial discharge capacity. Initial efficiency = (initial discharge capacity / initial charge capacity) * 100%.

[0075] Formation gas production test: Using an Archimedean balance, the battery is clamped with a string and placed in water. The balance is then read. The volume of gas generated during formation is calculated by measuring the difference between the discharge volume before and after the initial charge (charging at a current of 0.1C to a cutoff voltage of 4.55V and a cutoff current of 0.02C). Formation gas production = gas volume generated during formation / battery capacity.

[0076] Test of oxygen content in gas composition during the formation stage: gas chromatography is used for testing.

[0077] The results are shown in the following table: Table 2 Formation data of Examples 1 to 10 and Comparative Example 1

[0078] It can be seen from the formation data that, compared with Comparative Example 1, in Examples 1 to 10 to which the free radical scavenger 1,1-diphenyl-2-trinitrophenylhydrazine is added, the initial effects of Examples 1 to 10 are improved to varying degrees, the gas production is reduced, and the gas production decreases with the increase of the content of 1,1-diphenyl-2-trinitrophenylhydrazine, and the oxygen content in the gas also decreases, indicating that the free radical scavenger 1,1-diphenyl-2-trinitrophenylhydrazine can capture oxygen free radicals released by the lithium-rich manganese-based material due to phase change.

[0079] Battery cycle test Using a Blue Electric 5V 3A test cabinet, charge the battery to 4.35V at a constant current and voltage of 0.33C, with a cut-off current of 0.02C; then discharge the battery to 2.5V at a constant current of 0.33C. The battery was cycled 200 times, with the discharge capacity at the first cycle taken as the fractional capacity. The capacity retention rate after 200 cycles = (discharge capacity at the 200th cycle / discharge capacity at the first cycle) * 100%. The results are shown in Table 3: Table 3 Battery cycle test results of Examples 1 to 10 and Comparative Example 1

[0080] It can be seen from the battery cycle test results that the addition of 1,1-diphenyl-2-trinitrophenylhydrazine can improve the battery's cycle capacity retention rate and enhance the battery's cycle performance.

[0081] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "example," "specific example," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0082] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A battery, characterized in that: include: Positive electrode active material and 1,1-diphenyl-2-trinitrophenylhydrazine.

2. The battery according to claim 1, characterized in that The weight ratio of the 1,1-diphenyl-2-trinitrophenylhydrazine to the positive electrode active material is w, and the w satisfies: 0.1%≤w≤20%.

3. The battery according to claim 1, characterized in that The positive electrode active material includes positive electrode active material particles. A coating layer is provided on at least a portion of the positive electrode active material particles. The coating layer includes 1,1-diphenyl-2-trinitrophenylhydrazine.

4. The battery according to claim 3, characterized in that The thickness of the coating layer is d, wherein d satisfies: 0.2um≤d≤5um.

5. The battery according to any one of claims 1 to 4, characterized in that The positive electrode active material includes a layered oxide positive electrode active material and / or a phosphate-based positive electrode active material.

6. The battery according to any one of claims 1 to 5, characterized in that The positive electrode active material includes a lithium-rich manganese-based material.

7. The battery according to claim 6, characterized in that The positive electrode active material further includes lithium manganese iron phosphate material.

8. The battery according to claim 7, characterized in that The weight ratio of the lithium manganese iron phosphate material to the lithium-rich manganese-based material satisfies (85-90): (10-15).

9. The battery according to claim 7, characterized in that The positive electrode active material further includes lithium cobaltate and / or LiNixCoyMnzO2, x>0, y>0, z>0, x+y+z=1.

10. The battery according to claim 9, characterized in that The weight percentage of the lithium cobalt oxide and LiNixCoyMnzO2 to the weight percentage of the positive electrode active material is 1% to 99%, preferably 80% to 99%.

11. The battery according to any one of claims 1 to 10, characterized in that The battery includes a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode. The positive electrode includes the positive electrode active material. At least one of the positive electrode, the negative electrode, and the separator includes 1,1-diphenyl-2-trinitrophenylhydrazine.

12. The battery according to claim 11, characterized in that The positive electrode includes a positive electrode current collector and a positive electrode material supported on the positive electrode current collector. The positive electrode material includes the positive electrode active material and 1,1-diphenyl-2-trinitrophenylhydrazine.

13. The battery according to claim 11 or 12, characterized in that: The separator is coated with 1,1-diphenyl-2-trinitrophenylhydrazine.

14. The battery according to any one of claims 11 to 13, characterized in that: The battery further includes an electrolyte containing the 1,1-diphenyl-2-trinitrophenylhydrazine.

15. A battery pack, characterized in that: Comprising at least one battery according to any one of claims 1 to 14.

16. An electrical device, characterized in that: Comprising at least one battery pack according to claim 15.

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