Experimental comparison of fast-charging protocols for NMC and NCA Li-ion batteries

Abstract

Fast charging of lithium-ion batteries is today one of the key technological challenges to the wide adoption of electric vehicles. In recent years several charging protocols have been proposed, having the goal of reducing the charging time without hindering the battery life. Although several among these are promising, a comprehensive comparison among them is complicated by the fact that in the existing literature each has been tested with different cells and in specific conditions. This paper provides an overview as well as an experimental comparison of such protocols on two chemistries (NMC and NCA). It is found that out of the tested protocols, only the boost charging protocol reduces charging time by up to 9% as compared to the standard constant-current-constant-voltage (CCCV) protocol. However, it also decreases the cycle life of the cell by up to 14%. The pulse charging protocols, on the other hand, increase the charging time by up to 12% but provide and increase in cycle life by up to 167%, as compared to the CCCV protocol.