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Figure 3: CV curves of pure ZCO (a) and ZCO@C-5 composites (b) at 0.2 mV s−1 with a cut-off voltage range of 0.01-3.0 V. Discharge-charge profiles of pure ZCO (c) and ZCO@C-5 composites (d) in the 1st, 2nd, 3rd, and 30th cycles at 500 mA g−1.