AbstractThe intrinsic low conductivity, low tap density, and huge volume expansion during lithium storage severely restrict the practicality of micron‐silicon suboxide (m‐SiOx). Here, a carbon and MXene dual confinement and dense structural engineering strategy is proposed to construct m‐SiOx composites (m‐SiOx@C/MXene) through in situ carbon coating and electrostatic self‐assembly process. This integrated structural achieves a conductivity of 157 S cm−1 for m‐SiOx@C/MXene, which is 7 and 2 orders of magnitude higher than m‐SiOx (5.3 × 10−5 S cm−1) and m‐SiOx@C (2.9 S cm−1), respectively. The tap density of m‐SiOx@C/MXene reaches 1.35 g cm−3, significantly greater than that of m‐SiOx (0.82 g cm−3) and m‐SiOx@C (0.75 g cm−3). The 29% volume expansion of m‐SiOx@C/MXene during lithium storage is much lower than the 228% and 162% of m‐SiOx and m‐SiOx@C. The synergistic effect of the above advantages enables m‐SiOx@C/MXene to exhibit excellent rate performance and cycle stability. When assembled into a full cell with the LiFePO4 (LFP) cathode, it features high capacity retention and energy density of 99.1% and 380 Wh kg−1 after 100 cycles at 0.2 C. This work provides new reference for the stable structural design of m‐SiOx or other materials with huge volume expansion during energy storage.