Synergistic and capacitance effects in nanocarbon based capacitor batteries designed for superior rate capability and long-cycle stability

A novel concept of a high-power battery was designed to overcome the range anxiety of conventional lithium-ion batteries under fast charging. A synergistic effect between supercapacitors and lithium-ion batteries was achieved by introducing resin-based carbon nanospheres into the N0.6CM cathode material to construct hybrid electrodes, and a good size-matched spatial structure model of each component in the electrode material was achieved to ensure close electron contact and high tap density by controlling the size of the carbon nanosphere additives. To prepare a capacitive lithium-ion full battery, small-sized and highly conductive hard carbon derived from glucose with different defects was employed as the anode to match the above hybrid cathode. Finally, through our elaborate design, such as the optimization of hybrid cathodes, selection of hard-carbon anodes with suitable size and performance, and reasonable adjustment of anode and cathode ratios, we assembled a capacitor battery with a high capacity of more than 50% of the rated capacity at 10C and a reversible capacity retention rate of more than 85% at 1C for 200 cycles. [Display omitted] Existing lithium-ion batteries struggle to achieve high-rate discharge stability. To address this problem, this study combines resin-based carbon nanospheres with a double electric layer effect and cathode materials with lithium-ion intercalation/delithiation behavior to form a LiNi0.6Co0.2Mn0.2O2/resin-based carbon-sphere hybrid electrode. For further improvement in electron contact and tap density, the size of the carbon nanospheres was controlled by changing the synthetic parameters, and a size-matched spatial structure model of each component within the hybrid electrode was constructed. Considering the excellent rate capability of small-sized hard carbon, hard-carbon nanospheres derived from glucose were employed as the anode active material to assemble a capacitor battery. With the integration of characteristics of both lithium-ion batteries and supercapacitors, the as-prepared new capacitor battery exhibited a specific capacity of 146.1 mAh/g at 0.1C and an energy density of 474.5 Wh/kg on the cathode active material mass, a reversible capacity of 113.2 mAh/g at 1C after 200 cycles with retention of 85.3%, and the capacity remained at 82 mAh/g even at a high current rate of 10C. These results offer insights into the design of energy storage devices with excellent cycling stability and rate capability.