Anti-overcharge low-temperature rate type negative pole piece and manufacturing method thereof, and lithium ion battery based on negative pole piece

Abstract

The invention discloses an anti-overcharge low-temperature rate type negative pole piece and a manufacturing method thereof, and a lithium ion battery based on the negative pole piece, belonging to the technical field of lithium ion batteries. The manufacturing method comprises the following steps: uniformly mixing composite additive slurry and negative electrode slurry on a negative current collector and then conducting coating, or coating the composite additive slurry and the negative electrode slurry in a layered manner so as to obtain a coated electrode current collector; and drying the coated electrode current collector, and then conducting compacting to obtain the anti-overcharge low-temperature rate type negative electrode plate, wherein the composite additive slurry comprises the following components in percentage by mass: 0.1%-4% of an overcharge-preventing additive, 1%-6% of a conductive additive, 1%-6% of a heat-conducting additive and 0.1%-1% of a dispersing agent, with the balance being a solvent. According to the anti-overcharge low-temperature rate type negative pole piece prepared by the method and the lithium ion battery based on the negative pole piece, the lithium ion battery has excellent low-temperature discharge performance and rate discharge performance and good anti-overcharge safety performance, which are the key to solve problems in the prior art.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion batteries, and relates to an anti-overcharge low-temperature rate type negative pole piece, a manufacturing method thereof, and a lithium-ion battery based on the same. Background technique [0002] Lithium-ion batteries have been more and more widely used in daily production and life due to their significant advantages such as high energy density and long cycle life. However, since the potential difference between the positive and negative active materials used in lithium-ion batteries is generally above 2V, only an organic solvent electrolyte system with a wider electrochemical window can be used. Under extreme conditions, such as overcharging and overheating Under such circumstances, it is easy to cause the combustion of the organic electrolyte and cause serious safety accidents. At the same time, since graphite, silicon-carbon composite materials, and silicon oxide materials are mostly us...

AI Technical Summary

Problems solved by technology

However, the amount of its addition is closely related to the amount of liquid injected into the battery, and it cannot be accurately matched and coordinated with the positive sheet per unit area.

By using a low-temperature electrolyte and increasing the content of the conductive agent in the negative electrode sheet, the low-temperature rate performance can be effectively improved, but its heat dissipation performance is often not ideal, and the cycle life is poor under low-temperature or high-rate conditions.

[0004] In addition, the low-temperature discharge performance of conventional lithium-ion batteries is poor, and the performance declines severely below -10°C, and even cannot be discharged; the rate performance is not high, and when the 5C rate is continuously discharged, it will cause a higher temperature rise due to poor heat dissipation performance. , there is a risk of thermal runaway; at the same time, the abuse of user terminals may cause lithium-ion batteries to be overcharged, causing safety accidents such as combustion and explosion

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