Laser-modified graphitic onion-like carbon as anode for lithium/potassium-ion batteries

Graphitic onion-like carbon (GOC) presents a multi-shelled polyhedral structure with concentric arrangement of carbon layers. Used as anode material for lithium-ion batteries (LIBs) and potassium-ion batteries (PIBs), the concentric structure can effectively avoid interlayer slipping and ensure structural integrity, leading to higher cyclic stability than the normal anisotropic graphite such as the artificial and natural graphite. However, the confined multi-shelled structures of GOC will result in unsatisfactory electrochemical performance in reversible capacity and rate capability. Herein, a one-step laser-etched method was proposed to the surface modification of GOC by creating suitable pores and edge structures without destroying the intrinsic concentric structure. The laser-etched graphitic onion-like carbon (LGOC) delivers a high reversible capacity (436 mA h g−1 at 0.05 A g−1 in LIBs and 289 mA h g−1 at 0.1C in PIBs) and rate performance (89 mA h g−1 at 10 A g−1 in LIBs and 114 mA h g−1 at 2C in PIBs) with approximate initial coulombic efficiency. Meanwhile, the intrinsic concentric multi-shelled structure of LGOC facilitates structural integrity during lithium/potassium storage, possessing the intrinsic cyclic stability. This work provides an effective route for the application of GOC to replace traditional layered graphite materials as LIBs/PIBs anodes.