The demand for Lithium-ion batteries (LIBs) has been growing exponentially in recent years due to the proliferation of electric vehicles (EV). A large amount of lithium-ion batteries are expected to reach their end-of-life (EOL) within five to seven years. The improper disposal of EOL lithium-ion batteries generates enormous amounts of flammable and explosive hazardous waste. Therefore, cost-effectively recycling LIBs becomes urgent needs. Lithium nickel cobalt manganese oxides (NCM) are one of the most essential cathode materials for EV applications due to their long cycle life, high capacity, and low cost. In 2008, 18.9% of Lithium-ion batteries used NCM cathode material worldwide while this number increased to 31% six years later. An environment–friendly and low-cost direct recycling process for NCM has been developed in this project. The goal of this project is to recycle the EOL NCM and yield battery-grade NCM with equivalent electrochemical performance compared to virgin materials. In order to achieve this goal, four different heat treatment conditions are investigated during the direct recycling process. From the experimental results, the charge and discharge capacities of the recycled material are stable (between 151-155 mAh/g) which is similar to that of the commercial MTI NCM when sintered at 850 °C for 12 hours in the air. In addition, the cycling performance of recycled NCM is better than the commercial MTI NCM up to 100 cycles. / Master of Science / The demand for Lithium-ion batteries has been growing exponentially in recent years due to the proliferation of electric vehicles. A large amount of lithium-ion batteries are expected to reach their end-of-life within five to seven years. The improper disposal of end-of-life lithium-ion batteries generates enormous amounts of flammable and explosive hazardous waste. Therefore, cost-effectively recycling Lithium-ion batteries becomes urgent needs. Lithium nickel cobalt manganese oxides are one of the most essential cathode materials for electric vehicles applications due to their long cycle life, high capacity, and low cost. In 2008, 18.9% of Lithium-ion batteries used Lithium nickel cobalt manganese oxides cathode material worldwide while this number increased to 31% six years later. An environment–friendly and low-cost direct recycling process for Lithium nickel cobalt manganese oxides material has been developed in this project. The goal of this project is to recycle the end-of-life manganese oxides cathode material. In order to achieve this goal, four different heat treatment conditions are investigated during the direct recycling process. From the experimental results, the cycling performance of recycled NCM is better than the commercial MTI NCM.