Deep Cycling for High‐Capacity Li‐Ion Batteries

Abstract As the practical capacity of conventional Li‐ion batteries (LIBs) approaches the theoretical limit, which is determined by the rocking‐chair cycling architecture, a new cycling architecture with higher capacity is highly demanded for future development and electronic applications. Here, a deep‐cycling architecture intrinsically with a higher theoretical capacity limit than conventional rocking‐chair cycling architecture is developed, by introducing a follow‐up cycling process to contribute more capacity. The deep‐cycling architecture makes full use of movable ions in both of the electrolyte and electrodes for energy storage, rather than in either the electrolyte or the electrodes. Taking LiMn₂O₄‐mesocarbon microbeads (MCMB)/Li cells as a proof‐of‐concept, 57.7% more capacity is obtained. Moreover, the capacity retention is as high as 84.4% after 2000 charging/discharging cycles. The deep‐cycling architecture offers opportunities to break the theoretical capacity limit of conventional LIBs and makes high demands for new‐type of cathode materials, which will promote the development of next‐generation energy storage devices.