CNT-Assembled Octahedron Carbon-Encapsulated Cu3P/Cu Heterostructure by In Situ MOF-Derived Engineering for Superior Lithium Storage: Investigations by Experimental Implementation and First-Principles Calculation

Abstract

Conspicuously, metal–organic frameworks (MOFs) serve as homogenously and periodically atom-dispersed self-sacrificial template for in situ engineering of hierarchical porous carbon-encapsulated micro/nanoheterostructure materials, integrating the merits of micro/nanostructure to high-volumetric energy storage. Copper phosphide represents a promising candidate due to its compact material density compared to commercial graphite. Herein, micro/nanostructured Cu3P/Cu encapsulated by carbon-nanotube-assembled hierarchical octahedral carbonaceous matrix (Cu3P/Cu@CNHO) is constructed by an in situ MOF-derived engineering for novel anode material in LIBs, which achieves an extraordinary cycling stability (a well-maintained gravimetric/volumetric capacity of 463.2 mAh g−1/1878.4 mAh cm−3 at 1 A g−1 up to 1600 cycles) and distinguished rate capability (an ameliorated capacity of 317.7 mAh g−1 even at 10 A g−1), together with unprecedented heat-resistant capability (an elevated temperature of 50 °C for 1000 cycles maintaining 434.7 mAh g−1 at 0.5 A g−1). The superior electrochemical performance of Cu3P/Cu@CNHO is credited to the large specific surface area, conductive carbon matrix and metallic copper dopants, synergistic effects of the intrinsic Cu3P/Cu heterostructure, and well-defined micro/nanostructure, facilitating a boosted electrochemical conductivity and accelerated diffusion kinetics.