Prediction of metal recovery potential of end-of-life NEV batteries in China based on GRA-BiLSTM

Abstract

As Chinese new energy vehicle (NEV) sales continue to grow, end-of-life batteries have great potential for recycling in the future. In this study, a combined model based on Gray Relation Analysis and Bi-directional Long Short-Term Memory (GRA-BiLSTM) is proposed for predicting NEV sales, and the NEV battery life is modeled using the Weibull distribution. Then, the amount of end-of-life batteries, secondary utilization and metal recycling are calculated. The impact of end-of-life battery recycling on the supply and demand of key metals is studied. The results show that in 2040, the secondary utilization of end-of-life batteries in the Standard Growth Rate-Lithium Iron Phosphate Battery Dominated-High Secondary Utilization rate scenario (SGR-LFP_H) is 391.76 GWh. The recycling volumes of lithium, nickel and cobalt are 45,900 tons, 92,900 tons and 22,100 tons, respectively. In the Standard Growth Rate-lithium nickel cobalt manganese oxide Battery Dominated-Low Secondary Utilization rate scenario (SGR-NCM_L), the recycling of lithium, nickel and cobalt is even greater, at 62,600 tons, 372,200 tons and 71,700 tons, respectively. End-of-life batteries recycling can reduce the demand for metals. However, as NEV sales continue to grow, the gap between metal supply and demand remains significant. The findings urge the Chinese government develop appropriate battery management strategies to increase the recycling rate of end-of-life batteries; and to encourage enterprises to research new types of batteries to resolve the conflict between supply and demand for metals.