Anode Materials for High-Power Lithium-Ion Batteries
J. Michael Sieffert, Stephanie Bazylevych, Eric McCalla
Abstract
In the rapidly evolving rechargeable battery market, various applications lead to varied property requirements. One area that is emerging as essential is high-power batteries. These are expected to be able to charge and discharge in the order of minutes (slower than supercapacitors but faster than typical Li-ion batteries) and still have a high energy density (orders of magnitude higher than that of supercapacitors but lower than that of high-energy Li-ion batteries). In this space, anodes operating at a safe potential (near 1.5 V versus Li) sacrifice some energy density but enable fast cycling and lead to very safe batteries. In this review, we explore the plethora of materials being considered in the literature as potential high-power anodes. Though Nb-based anodes are prominent due to their recent popularity in the literature, any material classes leading to the appropriate balance of power and energy are discussed. We, in particular, aim to distinguish materials that are suitable only for supercapacitors from those with the potential for practical batteries, distinguished by volumetric energy density. The best materials discussed herein show excellent specific capacities and fast cycling performance, though a greater focus on performance at practical loadings is generally required.