2, Mechanical Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts, United States
Recycling of Li-ion batteries that have reached end-of-life (EOL) becomes increasingly critical to long term sustainability of electrochemical energy storage ecosystem, as the number of Li-ion battery powered portable devices and vehicles continues to increase rapidly. Many components incorporated in commercial Li-ion batteries face limited raw materials supply, such as Lithium, Nickel and Cobalt. Recovering those elements from spent batteries serves a dual purpose of reducing the environmental impact of hazardous materials disposal as well as providing a stable stream of the necessary metals to meet ever-growing manufacturing demand.
This research focused on evaluating nickel cobalt manganese oxide (NCM 111) cathode powder regenerated from a closed loop recycling process which targets end-of-life electric vehicle Li-ion batteries.[1-2] This process starts with spent batteries regardless of cathode chemistry, produces stoichiometric LiNi1/3Co1/3Mn1/3O2 (NCM 111) cathode material with electrochemical properties rivaling commercial control NCM 111. Prismatic pouch cells consist of recycled NCM 111 were fabricated at small and large capacity, 1.0 Ah and 11.0 Ah, respectively. Subsequent performance benchmarking against control cells was conducted through an array of metrics including rate capability HPPC, cold crank, cycle life and calendar life. Cells built with recycled NCM 111 demonstrated similar cyclability to control at >2500 cycles to 80% retention under +1C, -2C cycling conditions, and no obvious difference was observed for cold crank, HPPC and calendar life between commercial control and recycled cells. The rate capability, however, seems to slightly favor recycled cell at rates above 2C. Those results undoubtedly validate the recycled NCM 111 cathode as a legitimate contender for commercial electric vehicle Li-ion battery applications.
1. Gratz, E., Sa, Q., Apelian, D., Wang, Y., J. Power Sources 2014, 262, 255-262.
2. Sa, Q., Gratz, E., He, M., Lu, W., Apelian, D., Wang, Y., J. Power Sources 2015, 282, pp.140-145.