Nickel substituted LiMn2O4 cathode with durable high-rate capability for Li-ion batteries

Spinel LiMn2−xNixO4 (x = 0, 0.1, 0.2) nanoparticles were prepared through a simple one-step polymer-assisted chemical solution method. When x = 0.1, the cathode exhibited the best durable rate capability, with 100% of the capacity retained (∼100 mAh g−1) after 400 cycles at 10 C current rate. The excellent cyclability and rate capability originate from the thin carbon layer automatically formed from incomplete depolymerisation of polymers and the improved conductivity due to the nickel dopant. The improved conductivity was confirmed by less polarization at high current rate.