Synergistically engineered flexible/free-standing metals oxide and mixed metal oxides nanoclusters with reversible Na+ storage and enhanced initial coulombic efficiency

Abstract

The development of next-generation highly flexible materials as electrodes in sodium-ion batteries has significant potential. To overcome electrode deterioration and limited ionic and electronic mobility, surface-engineered materials are required. In this work, metal and mixed metal decorated freestanding CNFs electrodes exhibited quick diffusion kinetics as well as a substantial Na+ storage capacity. Mixed metal oxides exhibited ICE of 71% and a specific capacity of 489 mAh/g over 500 cycles, which is far better than metal oxides that demonstrated ICE of 43% and a specific capacity of 365mAh/g. This extraordinary synergy may encourage the development of advanced methods that combine self-supportive, highly flexible, and porous properties for further energy storage devices.