High-Entropy Engineering for Multivalency-Induced Stability in SnSb-Based Anodes

Achieving high energy density and long cycle life in alloy-type anodes remains a significant challenge due to the large volume changes during cycling. Here, we introduce a high-entropy engineering approach using SnSb-based oxides codoped with Ti and Al (SSBTA-600), designed to promote the formation of efficient oxygen vacancies at a calcination temperature of 600 °C. This approach results in remarkable performance with a capacity of 1012 mAh g^–1 at 0.5 A g^–1 and 297 mAh g^–1 at 5 A g^–1 after 500 cycles, with superior capacity retention of 99% and 83.5%, respectively. A LiFePO₄||SSBTA full cell achieves 134 mAh g^–1 after 100 cycles with 89.4% retention, demonstrating its practical potential for lithium-ion batteries. The high concentration of oxygen vacancies in SSBTA-600, induced by the multivalency of Ti and Al, is validated by electron paramagnetic resonance (EPR) and X-ray absorption spectroscopy (XAS). This high-entropy engineering approach significantly improves the cyclic stability and high-rate performance and provides a promising strategy for enhancing the energy density and cycle life in alloy-type anodes.