Novel Core-Dual Shell Si@MoO2@C Nanoparticles as Improved Anode Materials for Lithium-Ion Batteries

Silicon anode is one of the most potential large capacity anodes for the refreshing new generation of lithium-ion batteries. However, the volume changes greatly and the conductivity of Si anode is poor during the lithiation/delithiation process, resulting in inferior discharge/charge performance. To overcome these challenges, we design a core-dual shell Si@MoO2@C composite by solvent evaporation method and sol-gel method. The dual shell can surmount the considerable volume expansion as well as further the Li+/e(-) transport under the synergistic actions of the inner MoO2 and the outer carbon. The MoO2 shell can release the expansion pressure of Si as well as involve the storage of lithium effectively. The Si@MoO2@C anode shows a high ICE (about 80.3 %), a good specific capacity after 100 cycles (1171.7 mAh g(-1) at 1 A g(-1)), and a capacity retention of about 90.1 % (vs 2nd cycle). The excellent electrochemical performances are ascribed to the delicate design of the core-dual shell structure apparently, which make the Si@MoO2@C to be considered as an extremely promising anode material for LIBs.

Automated summary

The study presents a core-dual shell Si@MoO2@C composite to address the challenges of volume changes and poor conductivity in silicon anodes during the lithiation/delithiation process. The dual shell structure effectively overcomes the issues and results in high performance and cycling stability for lithium-ion batteries.