Synergistic engineering of structural and electronic regulation of In2Se3 for ultrastable Li- ion battery

As a representative two-dimensional layered material, In2Se3 attracts an increasing research interest because of the virtue of high theoretical lithium-ion storage capacity. However, the development of In2Se3-based anode is primarily confined by the poor electronic conductivity and inevitable volume variations. Moreover, the lithium -ion storage mechanism of In2Se3- based electrode is still not clear. Here, we report a facile construction strategy for metal-organic frameworks (MOFs)-derived In2Se3 nanocrystals encapsulated in porous nitrogen -doped carbon conductive matrix (In2Se3/PNC). The In2Se3/PNC with porous structure and rich N -doped carbon affords highly efficient channels for rapid transportation of ions and electrons. Meanwhile, as the het-erogeneous structure provides sufficient void space to relieve the internal mechanical stress during the repeated charge-discharge processes. Thus, the optimized In2Se3/PNC -800 (annealed at 800 degrees C) electrode exhibits a capacity as high as 1038 mAh/g at 200 mA g-1, remarkable cycling stability over 2000 cycles and a comparable high-rate capability. Moreover, the reaction mechanism of the In2Se3 with Li+ is revealed through in-situ XRD and density functional theory (DFT) simulations. This study may present broad opportunities for reliable construction of high-capacity selenium-based composites for energy storage.

Automated summary

In this study, a facile construction strategy for metal-organic frameworks (MOFs)-derived In2Se3 nanocrystals encapsulated in a porous nitrogen-doped carbon conductive matrix (In2Se3/PNC) was developed. The In2Se3/PNC exhibited a porous structure and abundant N-doped carbon, providing effective channels for the rapid transportation of ions and electrons. The optimized In2Se3/PNC-800 electrode showed a high capacity, remarkable cycling stability, and comparable high-rate capability.