Ever-Increasing Pseudocapacitance in RGO-MnO-RGO Sandwich Nanostructures for Ultrahigh-Rate Lithium Storage

Lithium ion batteries have attained great success in commercialization owing to their high energy density. However, the relatively delaying discharge/charge severely hinders their high power applications due to intrinsically diffusion‐controlled lithium storage of the electrode. This study demonstrates an ever‐increasing surface redox capacitive lithium storage originating from an unique microstructure evolution during cycling in a novel RGO–MnO–RGO sandwich nanostructure. Such surface pseudocapacitance is dynamically in equilibrium with diffusion‐controlled lithium storage, thereby achieving an unprecedented rate capability (331.9 mAh g−1 at 40 A g−1, 379 mAh g−1 after 4000 cycles at 15 A g−1) with outstanding cycle stability. The dynamic combination of surface and diffusion lithium storage of electrodes might open up possibilities for designing high‐power lithium ion batteries. Ever‐increasing surface redox capacitive lithium storage originating from a unique microstructure evolution during cycling is demonstrated in a novel RGO–MnO–RGO sandwich nanostructure. Such surface pseudocapacitance is dynamically in equilibrium with diffusion‐controlled lithium storage, achieving unprecedented rate capability with outstanding cycle stability. The dynamic combination of surface‐ and diffusion‐controlled lithium storage gives new insights into designing high‐power lithium ion batteries.