Binder migration: Frequently observed yet overlooked phenomena in electrode processing for lithium-ion batteries

Li-ion batteries (LIBs) are used in several applications, such as portable electronics and electric vehicles, owing to their high energy density, and longer cycle life. LIB's functionality and reliability are intensely improved by the binder materials used in the electrode assembling development. Classically polymeric compounds and binder materials are essential for electrode construction as they interlock active materials and conductive additives, granting mechanical stability and electron/ion transport pathways. Binder migration has numerous hostile impacts, incorporating diminished electrode stability, intensified internal resistance, defeat of active material exploitation, and prospective short-circuiting, which result in capacity weakening, declined cycle life, and compromised safety. Thus, the design of electrodes plays a crucial role in the performance of commercial rechargeable batteries, as their properties significantly impact battery cell performance. This review summarizes the reported phenomena of binder migration in both anode and cathode materials and discusses some of the attempted solutions to overcome or alleviate this issue. Some of the approaches that were taken to alleviate the binder migration issue as well as limitations of each approach are summarized. Finally, future perspectives are further presented to fully address the binder migration issue.