Combination of Lithium Battery Material Processing Technology and Microwave Sintering Technology

Lithium-ion batteries have become the ideal power supply for modern digital electronic products due to their advantages of high working voltage, high energy density, low self-discharge rate and stable environmental protection. With the development of the times and the progress of science and technology, lithium-ion batteries will develop along the road of environmental protection, high efficiency and low cost. Olivine-type lithium iron phosphate is the most promising cathode material for lithium-ion batteries because of its wide source of raw materials, low price and friendly environment. It has excellent thermal stability and high specific energy when used as cathode material.

At present, significant progress has been made in related research at home and abroad. Some enterprises have begun to produce and encountered some difficulties in industrialization. The main problems are as follows: (1) lithium iron phosphate has low conductivity and is only suitable for charging and discharging at low current density;

(2) Fe2+ is easy to be oxidized, and it is difficult to industrialize Fe2+ in the synthesis process; and

(3) Li+ diffusion channel is longer. Measures should be taken to reduce the particle size of the product;

(4) Improve the compacting density of the product. How to solve the above problems and further optimize the synthesis process will be the focus of future research. The sintering process of microwave equipment is a self-heating process by which objects absorb electromagnetic energy. It has the advantages of short heating time, high utilization rate of thermal energy and uniform heating. It has been applied in many materials heating. However, in the preparation of LiFePO4, ferrous oxalate is not a microwave acceptor. It is necessary to add microwave absorbing materials, such as activated carbon. On the one hand, activated carbon warms up rapidly in microwave field; on the other hand, it can produce reductive atmosphere at high temperature to prevent the oxidation of Fe2+. The microwave sintering method is simple in operation and short in synthesis time, which is suitable for laboratory research.