A Comprehensive Second-Life Review of Electric Vehicle Batteries - A Brazilian Study Case

Abstract

In terms of their high round-trip efficiency and energy density, LiBs can be used for long periods before reaching the end of their useful life. These aspects make them an extremely attractive option for application in EVs, in which they can be used for an estimated period of a decade. However, when removed from these vehicles, as they no longer provide the necessary requirements for this application, the batteries still have about 80% of their available storage capacity. For this reason, combined with its internal characteristics and the massive application in electric mobility, it is estimated that a significant portion of the batteries removed from EVs will be destined for a second use. In this scenario, CPFL Energia, in cooperation with CPQD and BYD Brazil, is developing an R&D project, which aims to assess the remaining useful life of LiBs removed from EVs in a second application. The EV batteries can be reused in stationary energy storage systems, which was the application considered to carry out an economic analysis that allowed the pricing of second-life cells at US$ 90.1/kWh. Thus, in parallel, laboratory tests were performedto characterize the cells, and algorithms are being developed to be integrated in these systems, with the purpose of allow the analysis of their health status and the forecast of remaining useful life in this second use, which is the motivation for the elaboration of this paper.