Battery, battery pack and electric device

Abstract

An electric device. The electric device comprises a battery pack, the battery pack comprises a battery, and the battery comprises a positive electrode active material and 1,1-diphenyl-2-trinitrophenylhydrazine.

Description

Batteries, battery packs and electrical equipment

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese patent application No. 202411548177.5, filed with the China National Intellectual Property Administration on October 31, 2024, entitled "Battery, Battery Pack and Electrical Equipment", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of battery technology, and in particular to a battery, battery pack and electrical device. Background Technology

[0004] In related technologies, at higher voltages (such as lithium batteries (Li+ / Li) at voltages greater than 4.5V), positive electrode active materials, such as lithium-rich phases, are prone to phase transitions. Lattice oxygen participates in electrochemical reactions, releasing active oxygen and dissolving metal ions. Active oxygen and metal ions easily catalyze the decomposition of the electrolyte, leading to poor battery cycle life, capacity decay, and reduced safety.

[0005] Public content

[0006] This disclosure aims to at least address one of the technical problems existing in the prior art. Therefore, the first objective of this disclosure is to provide a battery in which 1,1-diphenyl-2-trinitrophenylhydrazine captures active oxygen and metal ions released from the positive electrode active material, suppresses electrolyte side reactions, reduces battery gas production, and improves battery cycle performance.

[0007] The second objective of this disclosure is to propose a battery pack.

[0008] The third objective of this disclosure is to provide an electrical device.

[0009] The battery according to a first aspect embodiment of the present disclosure includes: a positive electrode active material and 1,1-diphenyl-2-trinitrophenylhydrazine.

[0010] According to the battery of the present disclosure, 1,1-diphenyl-2-trinitrophenylhydrazine acts as a free radical scavenger to capture active oxygen and metal ions released from the positive electrode active material, suppress electrolyte side reactions, reduce battery gas production, and improve battery cycle performance.

[0011] According to some embodiments of this disclosure, the weight ratio of 1,1-diphenyl-2-trinitrophenylhydrazine to the positive electrode active material is w, wherein w satisfies: 0.1% ≤ w ≤ 20%.

[0012] According to some embodiments of this disclosure, the positive electrode active material includes positive electrode active material particles, and at least a portion of the surface of the positive electrode active material particles is provided with a coating layer, the coating layer including the 1,1-diphenyl-2-trinitrophenylhydrazine.

[0013] According to some embodiments of this disclosure, the thickness of the coating layer is d, wherein d satisfies: 0.2um ≤ d ≤ 5um.

[0014] According to some embodiments of this disclosure, the positive electrode active material includes layered oxide positive electrode active materials and / or phosphate-based positive electrode active materials.

[0015] According to some embodiments of this disclosure, the positive electrode active material includes a lithium-rich manganese-based material.

[0016] According to some embodiments of this disclosure, the positive electrode active material also includes lithium manganese iron phosphate material.

[0017] According to some embodiments of this disclosure, the weight ratio of the lithium manganese iron phosphate material to the lithium-rich manganese-based material satisfies: (85-90):(10-15).

[0018] According to some embodiments of this disclosure, the positive electrode active material further includes lithium cobalt oxide and / or LiNixCoyMnzO2, wherein x > 0, y > 0, z > 0, and x + y + z = 1.

[0019] According to some embodiments of this disclosure, the weight percentage of the lithium cobalt oxide and the LiNixCoyMnzO2 in the positive electrode active material is 1% to 99%, preferably 10% to 15%.

[0020] According to some embodiments of this disclosure, 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.

[0021] According to some embodiments of this disclosure, the positive electrode includes a positive current collector and a positive electrode material loaded on the positive current collector, wherein the positive electrode material includes the positive electrode active material and the 1,1-diphenyl-2-trinitrophenylhydrazine.

[0022] According to some embodiments of this disclosure, the spacer is coated with the 1,1-diphenyl-2-trinitrophenylhydrazine.

[0023] According to some embodiments of this disclosure, the battery further includes an electrolyte containing the 1,1-diphenyl-2-trinitrophenylhydrazine.

[0024] A battery pack according to a second aspect of the present disclosure includes at least one battery according to the first aspect of the present disclosure described above.

[0025] An electrical appliance according to a third aspect of the present disclosure includes at least one battery pack according to a second aspect of the present disclosure described above.

[0026] Additional aspects and advantages of this disclosure will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this disclosure. Attached Figure Description

[0027] The above and / or additional aspects and advantages of this disclosure will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0028] Figure 1 is a schematic diagram of a cathode material according to an embodiment of the present disclosure;

[0029] Figure 2 is a schematic block diagram of a battery pack according to an embodiment of the present disclosure;

[0030] Figure 3 is a schematic block diagram of an electrical appliance according to an embodiment of the present disclosure;

[0031] Figure 4 is a schematic diagram of a battery according to an embodiment of the present disclosure.

[0032] Reference numerals: 1000, battery; 2000, battery pack; 3000, electrical equipment; 100, positive electrode active material; 10, positive electrode; 20, negative electrode; 300, separator; 400, positive electrode current collector; 1, positive electrode active material particles; 2, coating layer. Detailed Implementation

[0033] The battery 1000 according to a first aspect embodiment of the present disclosure is described below with reference to FIG1.

[0034] As shown in FIG1, the battery 1000 according to the first aspect embodiment of the present disclosure includes a positive electrode active material 100 and 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH).

[0035] The structural formula of 1,1-diphenyl-2-trinitrophenylhydrazine is as follows:

[0036] 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 exist stably. Its molecular formula is C1. 18 H 12 N5O6 has a molecular weight of 394.32, a purity of >98%, and a melting point of around 130℃.

[0037] 1,1-Diphenyl-2-trinitrophenylhydrazine, as a free radical scavenger, can capture oxygen free radicals and metal ions generated by the positive electrode active material 100 during operation, so that the battery 1000 has excellent electrochemical performance, which is beneficial to improving the cycle performance of the battery 1000, ensuring the capacity of the battery 1000, and improving the safety of the battery 1000.

[0038] 1,1-Diphenyl-2-trinitrophenylhydrazine exhibits good chemical and thermal stability, maintaining its activity even at relatively high temperatures (below 150°C). This is beneficial for enhancing the capture effect of 1,1-diphenyl-2-trinitrophenylhydrazine on oxygen free radicals and metal ions in the positive electrode active material 100 during the use of battery 1000. Furthermore, 1,1-diphenyl-2-trinitrophenylhydrazine has low toxicity, which helps reduce the environmental impact of battery 1000.

[0039] According to the battery 1000 of the present disclosure, 1,1-diphenyl-2-trinitrophenylhydrazine is used as a free radical scavenger to capture active oxygen and metal ions released by the positive electrode active material 100, suppress electrolyte side reactions, reduce the gas production of the battery 1000, and improve the cycle performance of the battery 1000.

[0040] The weight ratio of 1,1-diphenyl-2-trinitrophenylhydrazine to the positive electrode active material 100 is w, where w satisfies the condition: 0.1% ≤ w ≤ 20%. Therefore, by setting the weight ratio of 1,1-diphenyl-2-trinitrophenylhydrazine to the positive electrode active material 100 to 0.1% ≤ w ≤ 20%, the weight ratio of 1,1-diphenyl-2-trinitrophenylhydrazine to the positive electrode active material 100 is reasonably set. This allows 1,1-diphenyl-2-trinitrophenylhydrazine to effectively capture oxygen free radicals and metal ions in the positive electrode active material 100, while avoiding waste of 1,1-diphenyl-2-trinitrophenylhydrazine and ensuring the capacity of the battery 1000.

[0041] According to some embodiments of this disclosure, the positive electrode active material 100 includes positive electrode active material particles 1, and at least a portion of the surface of the positive electrode active material particles 1 is provided with a coating layer 2, which includes 1,1-diphenyl-2-trinitrophenylhydrazine. This arrangement allows DPPH to be uniformly distributed in the positive electrode active material 100, and the 1,1-diphenyl-2-trinitrophenylhydrazine can efficiently capture active oxygen and metal ions generated by the positive electrode active material particles 1, preventing these ions from reacting with the electrolyte, thereby improving the stability of the electrolyte and enhancing the electrochemical performance of the battery 1000.

[0042] Furthermore, the thickness of the coating layer 2 is d, where d satisfies: 0.2um ≤ d ≤ 5um. Therefore, by setting the thickness of the coating layer 2 to 0.2um ≤ d ≤ 5um, the thickness setting of the coating layer 2 is relatively reasonable. On the one hand, it facilitates the full capture of oxygen free radicals and metal ions in the positive electrode active material 100 by 1,1-diphenyl-2-trinitrophenylhydrazine; on the other hand, it avoids the situation where excessively thick coating layer 2 prevents lithium ions in the positive electrode active material 100 from quickly contacting the electrolyte, and also avoids the waste of 1,1-diphenyl-2-trinitrophenylhydrazine, thus ensuring the capacity of the battery 1000.

[0043] According to some embodiments of this disclosure, the positive electrode active material 100 includes layered oxide positive electrode active materials and / or phosphate-based positive electrode active materials. The layered oxide positive electrode active materials have a layered crystal structure; for example, they include one or more of lithium-rich manganese-based materials, lithium cobalt oxide, and LiNixCoyMnzO2. The phosphate-based positive electrode active materials include lithium manganese iron phosphate, lithium iron phosphate, etc. Phosphate-based positive electrode active materials exhibit good thermal and structural stability, enabling them to remain relatively safe even under overcharge or high-temperature conditions.

[0044] According to other embodiments of this disclosure, 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 high lithium content, and their chemical formula can be represented as xLi₂MnO₃·(1-x)LiTMO₂, where TM represents one or more transition metals such as nickel (Ni), manganese (Mn), and cobalt (Co). These materials are considered important candidates for next-generation lithium-ion battery positive electrode materials due to their extremely high theoretical specific capacity (over 350 mAh / g) and reversible specific capacity (greater than 250 mAh / g). Advantages include high capacity; the high specific capacity of lithium-rich manganese-based materials stems from their unique anionic redox reaction (O₂... - / O － / O2) and transition metal ions (such as Ni) 2+ / Ni 4+ Co 3+ / Co 4+ Mn 3+ / Mn 4+ The redox couple of manganese allows it to theoretically store more lithium ions, thus increasing the energy density of the battery by 1000. It is also low-cost, reducing the use of cobalt and nickel, lowering material costs, while the relatively abundant manganese resources facilitate large-scale commercial production.

[0045] During charging and discharging, lithium-rich manganese-based materials release active oxygen and / or dissolve metal ions. The phase transition process of these materials releases active oxygen, accelerating electrolyte catalytic oxidation, increasing side reactions in the battery 1000, and causing a sharp increase in impedance, leading to severe performance degradation. The free radical scavenger 1,1-diphenyl-2-trinitrophenylhydrazine can capture the active oxygen and metal ions released by the lithium-rich manganese-based materials, suppressing electrolyte side reactions, reducing gas production in the battery 1000, and improving its cycle performance.

[0046] According to some embodiments of this disclosure, the positive electrode active material 100 also includes lithium manganese iron phosphate. Lithium manganese iron phosphate has good thermal and chemical stability, and performs well in both high and low temperature environments. It also has high energy density and high operating voltage. Therefore, using lithium manganese iron phosphate as the positive electrode active material 100 is beneficial for improving the energy output of the battery 1000.

[0047] Lithium manganese iron phosphate (LiMnFePO4, or LMFP) is obtained by doping traditional lithium iron phosphate (LiFePO4, or 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, exhibiting a higher energy density than lithium iron phosphate. Key features and advantages include: High energy density: Due to manganese doping, the voltage platform of LMFP can be increased from approximately 3.4V of LFP to 3.8-4.1V, directly resulting in a theoretical energy density 10%-20% higher than LFP, approaching or sometimes even exceeding the level of some ternary materials. Safety: LMFP maintains a similar olivine-type structure to LFP. This structure has high stability and is not easily damaged even under extreme conditions (such as overcharging and high temperature), thus ensuring the safety of the battery 1000, superior to layered ternary materials. High cost-effectiveness: Avoiding the use of expensive nickel and cobalt reduces dependence on rare metals, resulting in a significant cost advantage. It is also compatible with LFP production lines, facilitating industrial production. At low temperatures, LMFPs exhibit better capacity retention than LFPs.

[0048] During charge and discharge, lithium manganese iron phosphate (LFP) materials exhibit significant impedance at the iron-manganese plateau transition and at the end of the manganese plateau, leading to increased polarization and performance degradation. Blending LFP with lithium-rich manganese-based materials leverages the interaction between the two materials to improve the cycle performance of battery 1000 during the iron plateau transition and the early and late manganese plateau stages. The manganese plateau of LFP operates at approximately 4.1V (vs. Li+ / Li), while the operating potential of lithium-rich manganese-based materials is also in a high-voltage region. Blending LFP with lithium-rich manganese-based materials can both increase the specific capacity of the positive electrode active material 100 and the operating voltage of battery 1000, thereby improving the energy density of battery 1000.

[0049] According to some embodiments of this disclosure, the weight ratio of lithium manganese iron phosphate material to lithium-rich manganese-based material satisfies (85-90):(10-15). For example, the weight ratio of lithium manganese iron phosphate material to lithium-rich manganese-based material can be any value among 86:14, 87:13, 88:12, and 89:11. Therefore, the weight ratio of lithium manganese iron phosphate material to lithium-rich manganese-based material is reasonable, allowing the two materials to fully interact and improve the cycle performance and energy density of battery 1000.

[0050] According to some specific embodiments of this disclosure, the positive electrode active material 100 further includes lithium cobalt oxide and / or LiNixCoyMnzO2 (x, y, z > 0, x + y + z = 1). Lithium cobalt oxide has advantages such as high operating voltage, stable discharge, high specific energy, and good cycle performance. LiNixCoyMnzO2 has high energy density, and the addition of Mn can improve the structural stability and safety of the positive electrode material. Co helps 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 decay at high temperatures, and improve the safety of the positive electrode active material 100.

[0051] The weight percentage of lithium cobalt oxide and LiNixCoyMnzO2 in the positive electrode active material 100 ranges from 1% to 99%. For example, the weight percentage of lithium cobalt oxide and LiNixCoyMnzO2 in the positive electrode active material 100 can be any value among 5%, 30%, 45%, 68%, 70%, 85%, and 95%. This helps to reduce the amount of lithium manganese-based materials used, thereby optimizing the composition and ratio of the positive electrode active material 100, improving its performance, and reducing its cost.

[0052] Preferably, the weight percentage of lithium cobalt oxide and LiNixCoyMnzO2 in the positive electrode active material 100 is 80% to 99%. For example, the weight percentage of lithium cobalt oxide and LiNixCoyMnzO2 in the positive electrode active material 100 can be any value among 85%, 87%, 90%, 93%, and 98%.

[0053] According to some embodiments of this disclosure, as shown in FIG4, the battery 1000 includes a positive electrode 10, a negative electrode 20, and a separator 300 disposed between the positive electrode 10 and the negative electrode 20. The positive electrode 10 includes a positive electrode active material 100. At least one of the positive electrode 10, the negative electrode 20, and the separator 300 includes 1,1-diphenyl-2-trinitrophenylhydrazine. By adding 1,1-diphenyl-2-trinitrophenylhydrazine to at least one of the positive electrode 10, the negative electrode 20, and the separator 300, it is beneficial to give full play to the role of 1,1-diphenyl-2-trinitrophenylhydrazine. That is, 1,1-diphenyl-2-trinitrophenylhydrazine can capture active oxygen and metal ions released by the positive electrode active material 100, suppress electrolyte side reactions, reduce the gas production of the battery 1000, and improve the cycle performance of the battery 1000.

[0054] Furthermore, the positive electrode 10 includes a positive electrode current collector 400 and a positive electrode material loaded on the positive electrode current collector 400. The positive electrode material includes a positive electrode active material 100 and 1,1-diphenyl-2-trinitrophenylhydrazine. The positive electrode current collector 400 provides an electron conduction path and acts as a supporting material to support the positive electrode material. The positive electrode current collector 400 collects electrons from the positive electrode material and guides them to the external circuitry of the battery 1000. The inclusion of 1,1-diphenyl-2-trinitrophenylhydrazine in the positive electrode material reduces the flow path of active oxygen and metal ions released from the positive electrode active material 100, allowing them to be quickly captured by the 1,1-diphenyl-2-trinitrophenylhydrazine, further reducing the gas production of the battery 1000 and improving the cycle performance of the battery 1000. In some embodiments, all of the 1,1-diphenyl-2-trinitrophenylhydrazine in the battery 1000 is added as part of the positive electrode material to the positive electrode 10.

[0055] According to some specific embodiments of this disclosure, the separator 300 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 of the battery 100 is 0.1% to 20%. For example, the weight percentage of 1,1-diphenyl-2-trinitrophenylhydrazine in the positive electrode active material 100 of the battery 1000 can be any value among 0.5%, 3%, 8%, 12%, and 18%. Therefore, including 0.1% to 20% by weight of 1,1-diphenyl-2-trinitrophenylhydrazine in the separator 300 of the battery 1000 is beneficial to improving the cycle performance and electrochemical performance of the battery 1000. 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 300, suppress side reactions in the electrolyte or separator 300, reduce the gas production of the battery 1000, improve the cycle performance of the battery 1000, and at the same time avoid adding too much 1,1-diphenyl-2-trinitrophenylhydrazine, which would result in an excessively thick separator 300.

[0056] In addition, the battery 1000 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 positive electrode material, improving the cycle performance and safety of the battery 1000.

[0057] For example, the preparation method of the cathode material includes the following steps:

[0058] The positive electrode active material 100 is obtained by premixing 1,1-diphenyl-2-trinitrophenylhydrazine.

[0059] According to the method for preparing the cathode material in this disclosure, premixing the cathode active material particles 1 and 1,1-diphenyl-2-trinitrophenylhydrazine helps to improve the distribution uniformity of 1,1-diphenyl-2-trinitrophenylhydrazine and the cathode active material particles 1, thereby improving the uniformity of the cathode material.

[0060] Furthermore, the premixing process 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 and preparation of the positive electrode material.

[0061] A battery pack 2000 according to a second aspect embodiment of the present disclosure includes at least one battery 1000 according to the first aspect embodiment of the present disclosure, as shown in FIG2.

[0062] The battery pack 2000 according to the embodiments of this disclosure is beneficial for improving the performance of the battery pack 2000, reducing the gas production of the battery pack 2000, and improving the stability and safety of the battery pack 2000. The battery pack 2000 can refer to a battery module, battery pack, etc.

[0063] The electrical device 3000 according to a third aspect embodiment of the present disclosure includes at least one battery pack 2000 according to the second aspect embodiment of the present disclosure, as shown in FIG3. The electrical device 3000 may refer to a vehicle, mobile electronic device, energy storage system, etc.

[0064] The electrical equipment 3000 according to the embodiments of this disclosure is beneficial to improving the operational stability of the electrical equipment 3000, enhancing the user experience, and improving the market competitiveness of the electrical equipment 3000.

[0065] The embodiments of this disclosure are described in detail below. It should be noted that the embodiments described below are exemplary and are only used to explain this disclosure, and should not be construed as limiting this disclosure. In addition, unless otherwise specified, all reagents used in the following embodiments are commercially available or can be synthesized according to the methods described herein or known to others. For reaction conditions not listed, they are also readily available to those skilled in the art.

[0066] Example 1

[0067] The preparation / composition of the positive electrode 10, negative electrode 20, separator 300, and electrolyte are as follows:

[0068] Positive electrode 10: Positive electrode active material 100 (positive electrode active material 100 includes LMFP and LLOS in 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 mixed in an N-methylpyrrolidone (NMP) solvent at a mass ratio of 96:2:2:5. After thorough mixing, the mixture is coated on both sides onto the positive electrode current collector 400 aluminum foil. After drying and rolling, the positive electrode 10 is obtained.

[0069] Negative electrode 20: 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 mixture of N-methylpyrrolidone and water) in a mass ratio of 100:1:0.7:0.8:1.5, coated on both sides of the negative electrode current collector copper foil, and obtained by drying and rolling.

[0070] Spacer 300: Made of polyethylene (PE) ceramic film.

[0071] Electrolyte: The lithium salt is lithium hexafluorophosphate (LiPF6), and the organic solvents include ethylene carbonate (EC), ethyl methyl carbonate (EMC), and dimethyl carbonate (DMC).

[0072] Examples 2-8

[0073] The batteries 1000 in Examples 2-8 are basically the same as those in Example 1, except that the relative contents of LMFP, LLOS or DPPH change, as detailed in Table 1.

[0074] Example 9

[0075] Example 9 differs from Example 1 in that the free radical scavenger DPPH is added to the negative electrode 20, and the amount of DPPH added accounts for 5% of the positive electrode active material 100. Specifically, the preparation / composition of the positive electrode 10, negative electrode 20, separator 300, and electrolyte are as follows:

[0076] Positive electrode 10: Positive electrode active material 100 (which includes LMFP and LLOS in a mass ratio of 85:15), conductive agent Ketjen black, and binder polyvinylidene fluoride (PVDF) are thoroughly stirred in N-methylpyrrolidone (NMP) solvent in a mass ratio of 96:2:2. After being mixed evenly, the mixture is coated on both sides of the positive electrode current collector 400 aluminum foil. After drying and rolling, positive electrode 10 is obtained.

[0077] Negative electrode 20: Graphite, SP conductive carbon black, sodium carboxymethyl cellulose (CMC-Na), styrene-butadiene rubber (SBR), polyacrylic acid binder (PAA), and DPPH are mixed and dispersed in a solvent (a mixture of N-methylpyrrolidone and water), and coated on both sides onto the negative electrode current collector copper foil. After drying and rolling, negative electrode 20 is obtained. The mass ratio of graphite, SP conductive carbon black, sodium carboxymethyl cellulose (CMC-Na), styrene-butadiene rubber (SBR), and polyacrylic acid binder (PAA) is 100:1:0.7:0.8:1.5; the amount of DPPH added accounts for 5% of the positive electrode active material 100.

[0078] Spacer 300: Made of polyethylene (PE) ceramic film.

[0079] Electrolyte: The lithium salt is lithium hexafluorophosphate (LiPF6), and the organic solvents include ethylene carbonate (EC), ethyl methyl carbonate (EMC), and dimethyl carbonate (DMC).

[0080] Example 10

[0081] Example 10 is basically the same as Example 1, except that a free radical scavenger DPPH is coated on the separator 300 at a weight ratio of 5% relative to the positive electrode active material 100 in the battery 1000. The amount of DPPH accounts for 5% of the positive electrode active material 100. Specifically, the preparation / composition of the positive electrode 10, negative electrode 20, separator 300, and electrolyte are as follows:

[0082] Positive electrode 10: Positive electrode active material 100 (which includes LMFP and LLOS in a mass ratio of 85:15), conductive agent Ketjen black, and binder polyvinylidene fluoride (PVDF) are thoroughly stirred in N-methylpyrrolidone (NMP) solvent in a mass ratio of 96:2:2. After being mixed evenly, the mixture is coated on both sides of the positive electrode current collector 400 aluminum foil. After drying and rolling, positive electrode 10 is obtained.

[0083] Negative electrode 20: 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 mixture of N-methylpyrrolidone and water) in a mass ratio of 100:1:0.7:0.8:1.5, coated on both sides of the negative electrode current collector copper foil, and obtained by drying and rolling.

[0084] The separator 300 is made of polyethylene (PE) ceramic film and coated with DPPH. The amount of DPPH accounts for 5% of the positive electrode active material 100.

[0085] Electrolyte: The lithium salt is lithium hexafluorophosphate (LiPF6), and the organic solvents include ethylene carbonate (EC), ethyl methyl carbonate (EMC), and dimethyl carbonate (DMC).

[0086] Comparative Example 1

[0087] The only difference between Comparative Example 1 and Example 1 is that it does not include DPPH.

[0088] Table 1. Component proportions of Examples 1-10 and Comparative Example 1

[0089] Examples 1-10 represent different experimental groups with the addition of the free radical scavenger 1,1-diphenyl-2-trinitrophenylhydrazine. Comparative Example 1 is a blank control group experiment without the addition of 1,1-diphenyl-2-trinitrophenylhydrazine. The positive electrode 10 from the experimental groups and comparative examples, along with a graphite negative electrode, separator 300, and electrolyte, were fabricated into a battery 1000 according to normal battery manufacturing procedures. The battery 1000 was designed to have a capacity of 700 mAh and underwent electrochemical testing in a battery testing cabinet.

[0090] Battery first efficiency and gas production test

[0091] The first charge-discharge test of battery 1000 was performed using the Blue Electric test cabinet. The battery was charged at 0.1C to a cutoff voltage of 4.55V, with a cutoff current of 0.02C, and the first charge capacity was recorded. The battery was then discharged at 0.1C to a cutoff voltage of 2.5V, and the first discharge capacity was recorded. First-time efficiency = (first discharge capacity / first charge capacity) * 100%.

[0092] Formation gas production test: An Archimedes balance was used for the test. Battery 1000 was clamped with a rope and placed in water. After standing, the balance data was read. The difference between the measured water displacement data before and after the first charge of battery 1000 (charging conditions: 0.1C current to a cutoff voltage of 4.55V, cutoff current of 0.02C) is the volume of gas produced during battery formation. Formation gas production = Volume of gas produced during formation / Battery capacity.

[0093] Oxygen content in the gaseous components during the formation stage was tested using gas chromatography.

[0094] The results are shown in the table below:

[0095] Table 2. Formation data for Examples 1-10 and Comparative Example 1

[0096] The formation data show that, compared with Comparative Example 1, Examples 1-10, which added the free radical scavenger 1,1-diphenyl-2-trinitrophenylhydrazine, all showed improved initial efficiency to varying degrees, while the gas production was reduced. The gas production decreased with increasing content of 1,1-diphenyl-2-trinitrophenylhydrazine, and the oxygen content in the gas also decreased. This indicates that the free radical scavenger 1,1-diphenyl-2-trinitrophenylhydrazine can capture oxygen free radicals released by lithium-rich manganese-based materials due to phase transition.

[0097] Battery Cycle Test

[0098] Using a Blue Electric 5V 3A test cabinet, the voltage was charged to 4.35V at a constant current and constant voltage of 0.33C, with a cutoff current of 0.02C; then discharged to 2.5V at a constant current of 0.33C. This charge-discharge cycle was repeated 200 times. The discharge capacity of the first cycle was taken as the initial capacity. The cycle capacity retention rate after 200 cycles was calculated as (discharge capacity of the 200th cycle / discharge capacity of the first cycle) * 100%. The results are shown in Table 3.

[0099] Table 3 Battery cycle test results of Examples 1-10 and Comparative Example 1

[0100] The battery cycle test results show that the addition of 1,1-diphenyl-2-trinitrophenylhydrazine can improve the cycle capacity retention rate of Battery 1000 and enhance its cycle performance.

[0101] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0102] Although embodiments of this disclosure have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this disclosure, the scope of which is defined by the claims and their equivalents.

Claims

1. A battery (1000), characterized in that, include: Positive electrode active material (100) and 1,1-diphenyl-2-trinitrophenylhydrazine.

2. The battery (1000) according to claim 1, characterized in that, The weight ratio of 1,1-diphenyl-2-trinitrophenylhydrazine to the positive electrode active material (100) is w, wherein w satisfies: 0.1% ≤ w ≤ 20%.

3. The battery (1000) according to claim 1 or 2, characterized in that, The positive electrode active material (100) includes positive electrode active material particles (1), and at least a portion of the positive electrode active material particles (1) are provided with a coating layer (2), the coating layer (2) including the 1,1-diphenyl-2-trinitrophenylhydrazine.

4. The battery (1000) according to claim 3, characterized in that, The thickness of the coating layer (2) is d, wherein d satisfies: 0.2um≤d≤5um.

5. The battery (1000) according to any one of claims 1-4, characterized in that, The positive electrode active material (100) includes layered oxide positive electrode active materials and / or phosphate-based positive electrode active materials.

6. The battery (1000) according to any one of claims 1-5, characterized in that, The positive electrode active material (100) includes lithium-rich manganese-based materials.

7. The battery (1000) according to claim 6, characterized in that, The positive electrode active material (100) also includes lithium manganese iron phosphate material.

8. The battery (1000) according to claim 7, characterized in that, The weight ratio of the lithium manganese iron phosphate material to the lithium-rich manganese-based material is (85-90):(10-15).

9. The battery (1000) according to any one of claims 1-8, characterized in that, The positive electrode active material (100) further includes lithium cobalt oxide and / or LiNixCoyMnzO2, wherein x>0, y>0, z>0, and x+y+z=1.

10. The battery (1000) according to claim 9, characterized in that, The weight percentage of the lithium cobalt oxide and the LiNixCoyMnzO2 in the positive electrode active material (100) is 1% to 99%, preferably 10% to 15%.

11. The battery (1000) according to any one of claims 1-10, characterized in that, The battery (1000) includes a positive electrode (10), a negative electrode (20), and a separator (300) disposed between the positive electrode (10) and the negative electrode (20). The positive electrode (10) includes the positive electrode active material (100), and at least one of the positive electrode (10), the negative electrode (20), and the separator (300) includes the 1,1-diphenyl-2-trinitrophenylhydrazine.

12. The battery (1000) according to claim 11, characterized in that, The positive electrode (10) includes a positive electrode current collector (400) and a positive electrode material loaded on the positive electrode current collector (400). The positive electrode material includes the positive electrode active material (100) and the 1,1-diphenyl-2-trinitrophenylhydrazine.

13. The battery (1000) according to claim 11 or 12, characterized in that, The separator (300) is coated with the 1,1-diphenyl-2-trinitrophenylhydrazine.

14. The battery (1000) according to any one of claims 11-13, characterized in that, The battery (1000) further includes an electrolyte containing the 1,1-diphenyl-2-trinitrophenylhydrazine.

15. A battery pack (2000), characterized in that, Includes at least one battery (1000) according to any one of claims 1-14.

16. An electrical appliance (3000), characterized in that, Includes at least one battery pack (2000) as claimed in claim 15.

Images