Nanocrystalline C-Ni Hybrid Nanoporous Monoliths for Large-Capacity and Ultrahigh-Rate Energy Storage

Graphene material is promising for harmonizing supercapacitor-like power density and battery-level energy density into one electrochemical energy storage (EES) system. Cost-effective, controlled, and massive production of graphene material and its successful application in practical EES are two significant challenges yet to be resolved. By developing a simple nickel nitrate-based hard-template preparation, this study demonstrates the smart design of nanocrystalline C-Ni hybrid monoliths with three-dimensionally ordered macroporous (3DOM) frameworks for high-efficiency EES. The abundant Li-storage sites and mixed high electronic and ionic conductivities grant such freestanding C-Ni composite electrode material large reversible capacity and high-rate capability through thousands of cycles even at a great thickness and using no extra current collector. This 3DOM strategy will facilitate real EES applications of graphene materials, and the yielded nanocrystalline-graphene material is promising to replace graphite anodes in current commercial LIBs with limited performances.