Tailoring Porous Transition Metal Oxide for High-Performance Lithium Storage

High-capacity conversion-type anodes suffer from sluggish ion/electron migration and tremendous mechanical degradations, severely restricting the cyclic performance in LIBs. The mentioned disadvantages can be efficiently eliminated by the development of electrode materials with gradient structure, decreased ion diffusion pathway, and enough reserve space. Herein, a new type 3D-interconnected hollow structure assembled by porous Co3O4 nanoparticles (HG-Co3O4@void) is proposed and fabricated as lithium-ion storage. HG-Co3O4@void exhibits high reversible capacity, superior rate performance, and long-term cycle stability (619 mAh g–1 after 500 cycles at 5 A g–1). The superior performance is attributed to the synergistic effects between large void space and massive ion channels, both which offer robust structure integrity and ultrafast Li+ transport inside HG-Co3O4@void. Besides, the prominent pseudocapacitive behavior induced by three-dimensional accessibility nanoarchitecture led to the ultrahigh rate capability. This work provides a promising way to structure functional materials for electrochemical energy storage technologies.