Cobalt–Manganese Mixed-Sulfide Nanocages Encapsulated by Reduced Graphene Oxide: In Situ Sacrificial Template Synthesis and Superior Lithium Storage Properties

5 years ago

Cobalt–Manganese Mixed-Sulfide Nanocages Encapsulated by Reduced Graphene Oxide: In Situ Sacrificial Template Synthesis and Superior Lithium Storage Properties

Xiuling Jiao, Fangchun Han, Dairong Chen, Cheng Li

This work demonstrates a facile in situ synthesis of cobalt–manganese mixed sulfide (CoMn-S) nanocages on reduced graphene oxide (RGO) sheets by using a crystalline Co–Mn precursor as the sacrificial template. The CoMn-S/RGO hybrid was applied as the anode for Li-ion storage and exhibited superior specific capacity, excellent cycling performance, and great rate capability. In particular, lithium storage testing revealed that the hybrid delivered high discharge–charge capacities of 670 mA h g−1 at 1.0 A g−1 after 400 cycles and 925 mA h g−1 at 0.1 A g−1 after 300 cycles. The outstanding electrochemical performance of CoMn-S/RGO is attributed to the close entanglement of nanocages with RGO nanosheets achieved by the synthetic method, which greatly improves ion/electron transport along the interfaces and efficiently mitigates volume dilation during lithium reactions. This rational design of both the composition and architecture of mixed metal sulfides can be expanded to other composite systems for high-capacity Li-ion batteries and provides a unique insight into the development of advanced hybrid electrode materials. Greater than the sum of its parts: A rational compositional and architectural design of mixed-transition-metal sulfides in hybridization with reduced graphene oxide has led to superior anode materials with high capacity and cycling performance for Li-ion batteries (see figure; TAA=thioacetamide).

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/asia.201700722