Abstract: With the recent rapid development of electric vehicles, the use and decommissioning of Li-ion batteries have increased, causing environmental pollution and the waste of valuable materials in spent batteries. Commercial Li-ion batteries are mostly composed of transition metal oxide or phosphate-based cathodes, graphite-based anodes, organic electrolytes containing harmful lithium salts, polymer separators, and plastic or metal shells. After the battery is retired, many precious metals and graphite have a high recycling value. We review the current status of research on recovering these components with an emphasis on the leaching and separation of cathode and anode materials, and electrolytes in these batteries. The problems encountered in the different methods are outlined in terms of recycling cost and secondary pollution. Future research trends are outlined for the commercial full recovery of spent Li-ion batteries.