Power battery using mixed anode material

Abstract

The invention relates to a power battery using mixed anode material. An anode comprises an active substance, a conductive agent, a binder and a solution, wherein a mixed material of lithium iron phosphate and nickel-manganese-cobalt ternary material is used as the active substance; and the components are as follows in percentage by weight: 5 to 95 percent of lithium iron phosphate, 1 to 20 percent of conductive agent and 2 to 10 percent of binder. The conductive agent comprises acetylene black and carbon black; polyvinylidene fluoride is adopted as the binder; and N-N-dimethyl pyrrole is adopted as the solvent. Compared with a traditional lithium iron phosphate power battery, the power battery has the following advantages: the working voltage ranges from 2.75 to 4.2 volts, and is superior to that of the lithium iron phosphate battery; good high temperature performance is achieved; good low temperature performance is achieved, and discharge capacity is more than 90 percent at 0 DEG C; excellent security feature is achieved, and overcharge resistance is consistent to that of the lithium iron phosphate; and high energy density is achieved: the compacted density of the lithium iron phosphate ranges from 2.0 to 2.1, the compacted density of nickel-manganese-cobalt ternary material ranges from 3.4 to 3.8, and the compacted density of the mixture can range from 2.2 to 2.9.

Description

technical field [0001] The invention relates to a power battery, in particular to a power battery whose positive electrode adopts nickel-manganese-cobalt ternary material and lithium iron phosphate mixed material. Background technique [0002] Lithium iron phosphate has been widely used in the field of power batteries. Along with its advantages of high safety and high cycle life, lithium iron phosphate batteries also have obvious disadvantages, such as poor conductivity and slow diffusion of lithium ions; high-rate charging When discharging, the actual specific capacity is lower. The above problems are the difficulties restricting the development of lithium iron phosphate battery industry, and it is also a main reason why lithium iron phosphate has not been widely used so far. [0003] At present, the problem of poor conductivity of lithium iron phosphate has been better solved, and the usual method is to add carbon (C) or other conductive agents. In the actual production ...

AI Technical Summary

Problems solved by technology

Such low temperature performance obviously cannot meet the requirements of the power supply.

At present, some manufacturers have improved the low-temperature performance of lithium iron phosphate by improving the electrolyte system, improving the positive electrode formula, improving material properties and improving the structure design of the battery cell, but it has not really met the demand.

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