Enabling 10C-rate fast charging in LiFePO4 based lithium-ion battery by balancing the electronic and ionic conductivity paths in cathode

The challenge of high-rate charging remains a critical barrier for the widespread adoption of lithium-ion batteries (LIBs). In this study, we address this issue by employing a novel binder, poly(methyl methacrylate)-grafted-natural rubber (PMMA- g -NR), for lithium iron phosphate (LFP) cathodes. This amphiphilic binder not only improves ionic and electronic conductivities but also prevents macro-phase segregation of LFP and conductive carbon, ensuring uniform distribution. The unique microphase morphology, governed by the “like dissolves like” principle, enriches conductive carbon in NR domains and LFP particles in PMMA domains, enhancing the synergy between the ionic and electronic transport pathways. The resulting LFP||Li cells exhibit exceptional rate performance, maintaining 64% capacity retention after 1200 cycles at 10C. Furthermore, the binder’s excellent elasticity preserves electrode integrity during repeated cycling. This work highlights the critical role of binder design in advancing high-rate charging capabilities, offering a scalable solution to improve the fast-charging performance and longevity of LIBs.