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

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. (C) 2022 Elsevier Inc. All rights reserved.

Automated summary

This study successfully combines resin-based carbon nanospheres with cathode materials to form a hybrid electrode, and further improves electron contact and tap density by controlling the size of carbon nanospheres and constructing a size-matched spatial structure model. A capacitor battery assembled with hard-carbon nanospheres as the anode active material exhibits excellent rate capability and cycling stability.