Improving the high-voltage high-rate performance of a P2 layered oxide cathode by a dual-ion doping strategy for sodium-ion batteries

Synergy between Ti 4+ and F − dual-doping significantly improves the cycling stability of P2-Na 0.67 Ni 0.33 Mn 0.67 O 2 at high voltage and enhances its rate performance by suppressing the P2–O2 transition.