• Trace Ce doping significantly enhances the activation performance of V78Ti6Cr16 alloy.
• V78Ti6Cr16Ce0.2 achieves 97.43% capacity retention after 400 cycles, vs 93.06% for undoped, with >90% retention after 1000 cycles.
• Ce doping increases cell volume and mechanical properties, improving structural stability during cycling.
• The superior cycling stability of Ce-doped alloy is attributed to reduced defect density compared to undoped alloy.