A wide temperature electrolyte for ternary manganese-doped lithium battery and preparation method thereof

Abstract

The invention discloses a wide temperature electrolyte solution for a ternary manganese-doped lithium battery and a preparation method thereof, belonging to the technical field of lithium ion batteries. The electrolyte solution is mainly made of the following components in mass fraction: lithium salt 12%~ 15%, 80%-85% of organic solvent and 2%-6% of additives, the additives include vinylene carbonate, 1,3-propane sultone, lithium difluorooxalate borate and lithium difluorophosphate. It has excellent electrochemical performance, good stability, wide operating temperature range, and can be used under high temperature and low temperature conditions. At -40°C, 0.2C discharge cycle for 500 cycles, the capacity retention rate is about 80.30%-85.49%; at 60°C for 7 days, there is no skinning and flatulence, and the capacity retention rate is about 92.89%-95.72%. The charge recovery rate is about 99.39%‑101.39%. The preparation method of the electrolyte has the advantages of simple process, convenient production, high production efficiency and good quality of produced products.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion batteries, and in particular relates to a wide-temperature electrolyte for ternary manganese-doped lithium batteries and a preparation method thereof. Background technique [0002] Lithium battery is a new generation of green and environment-friendly battery. It has the characteristics of high voltage, large specific energy, long charge and discharge life, safety and environmental protection, and has become the leading portable power source and power source. At present, the discharge capacity of lithium-ion batteries equipped with conventional electrolytes is only about 80% at -20°C, and basically no electricity can be discharged at -40°C, which greatly limits lithium-ion batteries in severe cold areas such as Inner Mongolia, Heilongjiang, and northern Gansu. In addition, as we all know, the car driving recorder needs high temperature resistance, because the temperature of the car may reach ab...

AI Technical Summary

Problems solved by technology

Not only that, when lithium-ion batteries are charged at low temperatures, lithium ions may not have time to intercalate into the graphite negative electrode, thus forming lithium metal dendrites on the surface of the negative electrode. This reaction will consume lithium ions in the battery that can be repeatedly charged and discharged, and reduce the conductivity. , and greatly reduce the battery capacity, the precipitated metal lithium dendrites may also increase the resistance of the SEI film, and may pierce the separator, thus affecting the safety performance

At present, the industry usually improves the low-temperature performance of lithium batteries by introducing linear carboxylate solvents into the electrolyte, but such solvents have a greater impact on cycle performance and cannot be used at high temperatures

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