Mass Loading-Independent Lithium Storage of Transitional Metal Compounds Achieved by Multi-Dimensional Synergistic...

Nanostructured transitional metal compounds (TMCs) have demonstrated extraordinary promise for high-efficient and rapid lithium storage. However, good performance is usually limited to electrodes with low mass loading (≤1.0 mg cm^-2 ) and is difficult to realize at higher mass loading due to increased electrons/ions transport limitations in the thicker electrode. Herein, the multi-dimensional synergistic nanoarchitecture design of graphene-wrapped MnO@carbon microcapsules (capsule-like MnO@C-G) is reported, which demonstrates impressive mass loading-independent lithium storage properties. Highly porous MnO nanoclusters assembled by 0D nanocrystals facilitate sufficient electrolyte infiltration and shorten the solid-state ions transport path. 1D carbon shell, 2D graphene, and 3D continuous network with tight interconnection accelerate electrons transport inside the thick electrode. The capsule-like MnO@C-G delivers ultrahigh gravimetric capacity retention of 91.0% as the mass loading increases 4.3 times, while the areal capacities increase linearly with the mass loading at various current densities. Specifically, the capsule-like MnO@C electrode delivers a remarkable areal capacity of 2.0 mAh cm^-2 at a mass loading of 3.0 mg cm^-2 . Moreover, the capsule-like MnO@C also demonstrates excellent performance in full battery applications. This study demonstrates the effectiveness of multi-dimensional synergistic nanoarchitecture in achieving mass loading-independent performance, which can be extended to other TMCs for electrochemical energy storage.