Material flow of nickel in nickel metal hydride batteries waste and possible circularity improvement in Thailand

Abstract

Hybrid vehicles are becoming more popular in Thailand. The battery that is used in hybrid vehicles is nickel metal hydride battery (Ni-MH). However, there is no management plan in dealing with Ni-MH batter wastes. It needs to be developed. This study applied material flow analysis (MFA) as a tool to trace nickel flow and stock in Ni-MH batteries supply chain in Thailand in order to analyze the current status of Ni-MH management and ways of improving circular economy. The authors calculated Material Circularity Indicator for a product (MCIp) and used it as an indicator of circular economy. In 2018, a total of 3414 tons of nickel in the used Ni-MH batteries were sent to Japan for recycling from Thailand. Because the efficiency of recycling was 95%, only 3243 tons of nickel were obtained in this process and sent to a battery pack manufacturing factory. The total quantity of batteries that was repacked was equivalent to 1921 tons of nickel a year. The domestic MCIp is 0.424, and the transboundary MCIp of nickel in NI-MH batteries in Thailand is 0.971, suggesting that even though looking at the global view, it has good circular system but for domestic view, Thailand is still far away from fully circularity. It would be better if Thailand had its recycling factory and did not have to ship materials to Japan for recycling. The shipment is costly and contributes to the greenhouse effect. Graphical abstract: [Figure not available: see fulltext.]