Introduction to crushing and separation technology for power lithium batteries

With the scarcity of power batteries in the automotive industry, Zhang Xiang, a researcher at the Automotive Industry Innovation Research Center of North China Industrial University, noted that the average industry capacity utilization rate is only around 30%. Quality high-density battery production capacity is tight, with companies like CATL operating at 90% utilization rates. The performance of new energy vehicle power batteries declines with usage. According to industry standards, when the power battery declines to below 80% of new battery (range), it is usually around 1000 cycles for ternary lithium batteries, and 2500 cycles for lithium iron phosphate batteries, after which the battery is no longer suitable for use in new energy vehicles. As technology updates, demand for new types of batteries is increasing, but production capacity is struggling to keep pace. Raw material scarcity is one of the big issues. Retired lithium batteries need to be recycled and reused.

Retired power batteries can be used in other fields, such as energy storage, to fully leverage their remaining value. Another recycling option is to disassemble the retired batteries, discharge them, and extract the raw materials, allowing for their reuse in a circular economy. Today, we will mainly discuss the disassembly technology of lithium batteries – lithium battery crushing and sorting.

The production line for the crushing and sorting of charged lithium batteries typically consists of the following equipment: a charged lithium battery crusher, electrolytic hot evaporation device, pole piece friction powder removal and airflow grading equipment, a comprehensive lithium battery crushing and sorting device, an automatic lithium battery discharge device, and an anaerobic cracking furnace. The specific plan for each line is determined based on different needs.

The charged lithium battery undergoes crushing under low oxygen conditions and then enters low oxygen heating and volatilization. The first step of volatilization is nitrogen-free thermal volatilization, which can reduce nitrogen usage. The second step is heating nitrogen volatilization and automatic extraction volatilization gas system. (The temperature of the thermal volatilized material is less than 140 degrees, avoiding softening of the plastic film into a lump). Volatilization ensures an oxygen content of less than 1%. Heating and volatilization utilize cracking combustion exhaust and electric power generation from charged lithium batteries’ heating to achieve electric discharge and reuse of cracking exhaust heat. The combustion system improves the safety of equipment operation, and the extracted electrolyte gas is transported separately to the cracking combustion system for heating. This is to prevent the explosion of organic gas containing oxygen and to achieve comprehensive utilization of sorting and volatilization exhaust gas.