Sacrificing Initial Active Area for Superior Structural and Interfacial Stability in MoSe 2 /C Anodes for All‐Solid‐State Lithium Batteries

ABSTRACT Conversion‐type materials for all‐solid‐state lithium batteries face low conductivity, sluggish kinetics, severe volume expansion, and unstable interfaces. Herein, a MoSe 2 /C composite is fabricated via a wet‐chemical synthesis approach combined with shell engineering. Density functional theory calculations show that the carbon skeleton enhances conductivity, improves Li + adsorption, and lowers the diffusion barrier. In situ and finite element analyses confirm that the hollow carbon mitigates volume expansion and redistributes stress. Distribution of relaxation times analysis reveals that stress buffering suppresses interfacial degradation and enhances Li + migration. Pseudocapacitive analysis shows a slightly higher contribution for pristine MoSe 2 due to face‐to‐face stacking versus point‐contact packing in MoSe 2 /C, which sacrifices some initial active area. However, the carbon skeleton accelerates the kinetics of the remaining active regions and provides excellent stress buffering and interfacial stability. Consequently, the MoSe 2 /C anode exhibits rate capability and long‐term cycling performance in both half‐cells (11 000 cycles at 3 A g −1 ) and full‐cells (200 cycles at 0.1 C). This work proposes a counterintuitive strategy of “trading part of the initial active area in exchange for superior structural and interfacial stability,” offering a rational design paradigm for conversion‐type materials.