Synthesis of Cobalt‐Doped Tin‐Based Metal Phosphides/MXene Hybrids With Improved Sodium Storage Performance

Tin phosphide (Sn 4 P 3 ) has emerged as a potential anode material for sodium‐ion batteries (SIBs) because of the exceptional theoretical capacity and favorable redox potential. However, the practical application of Sn 4 P 3 in SIBs has been hindered by significant challenges, including rapid capacity fading and inherently low electrical conductivity. To address the issue, we developed a novel CoSnP x /MXene composite through a hydrothermal synthesis followed by phosphidation, which effectively incorporates cobalt‐doped Sn 4 P 3 nanoparticles into the MXene matrix. The combination of cobalt doping and the MXene conductive network effectively accommodates the volume expansion and prevents tin aggregation during sodiation /desodiation processes, while simultaneously enhancing ionic and electronic transport kinetics. As a result, the optimized CoSnP x /MXene‐3:1 delivers exceptional reversible capacities of 473.9, 241.3, and 208.8 mAh g −1 at 0.1, 1.0, and 5.0 A g −1 , respectively. These findings demonstrate that appropriate cobalt doping coupled with MXene incorporation can significantly improve the rate capability and cycling stability of Sn 4 P 3 ‐based electrodes.