Toxicity analysis of second use lithium-ion battery separator and electrolyte

Pyrolysis gas chromatography-mass spectrometry (Py-GC-MS) test, smoke toxicity analysis and mouse biological toxicity test were carried out on the second use lithium-ion battery separator and electrolyte. It was found that the types of cracked products of separator and electrolyte under different state of health (SOH) were basically the same, mainly phosphoryl fluoride (POF₃) and long-chain F-containing alkanes, alcohols and esters. The content of POF₃ in the cracked product increases as the SOH increases. The toxic gas components released after the separator and the electrolyte are completely burned mainly include CO, CO₂, and HF. The HF content decreased as the battery SOH decreased, from 101.6 mg/g of the 100% SOH battery to 44.1 mg/g of the 65% SOH battery. In the biological toxicity test, all the mice were found to stop running, close eyes, shed tears, and have shortness of breath. After the test, only 65% SOH and 100% SOH mice recovered their body weight to the pre-experimental average state and gained weight.