Accurate regulation of pore distribution and atomic arrangement enabling highly efficient dual-carbon lithium ion capacitors

Abstract

The pore structure and atomic arrangement of nanosized carbon are accurately regulated by the smart combination of in situ graphitization and self-activation effect. Benefiting from the scalpel-like regulation of the ratio between the catalyst and activator, ordered–disordered hybrid graphitic carbon anodes with abundant pores are achieved. Especially, the GCFs-3 sample delivers a plateau capacity of 285.3 mA h g⁻¹ even at 0.1 A g⁻¹ in Li-half cells, and possesses fast charge–discharge capability at high rates. Further, the self-activated mesoporous carbon with specific surface area as high as 1522.2 m² g⁻¹ exhibits a high specific capacity of 56.6 mA h g⁻¹ (vs. 45.1 mA h g⁻¹ of commercial activated carbon) at 0.05 A g⁻¹. The superior-rate graphitic carbon negative electrode and high-specific-capacity mesoporous activated carbon positive electrode satisfy perfectly the demand for high-energy-density and superior-power-output dual-carbon lithium-ion capacitors (LICs). When assembled into LICs, high energy density (86.4 W h kg⁻¹, 62.2 W kg⁻¹), excellent power density (19.8 kW kg⁻¹, 60.3 W h kg⁻¹) and long-term cycling stability (98.1% after 20 000 times at 5.0 A g⁻¹) are achieved, outperforming the state-of-the-art LIC configurations. This tactic opens a new window for the design of electrode materials via utilizing the synergistic effect between the catalyst and activator to adjust the microstructures.