Electrochemical performance of O3-NaNCMMT electrode. (a) Galvanostatic charge/discharge curves versus specific capacity at 0.2C in the voltage range of 2.0-4.0 V. (b) Cyclic voltammograms at 0.1 mV s-1 in different cycles. (c, d) Rate performance at various rates and corresponding galvanostatic charge/discharge curves versus specific capacity. (e) Midpoint voltage and energy efficiency. (f, g) GITT curves and corresponding voltage polarization with ohmic polarization. (h, i) Cyclic voltammograms at different scan rates and corresponding linear fitting of peak current versus square root of the scan rate at different oxidation peaks. (j) Cycling performance during 1000 cycles at 5C after performance tests at various rates.