The effects of near surface and bulk microstructure on lithium intercalation of disordered, `'hard' carbons

摘要

Disordered cargbons were synthesized at 700 deg C from methacrylonitrile-divinylbenzene carbons were subjected to rapid surface heating by a pulsed infrared laser. While the bulk structure remained essentially unchanged, there was substantial surface reconstruction to a depth of 0.25 mu m after heating (5.9 W average power at 10Hz, 10 ns pulse with, 1064nm wavelength). The surface ordering appears similar to the bulk microstructure of carbons isothermally annealed at 2.200 deg C(i.e., turbostratic). Inprovements were observed in first cycle irreversible loss, rate capability, and conulombic efficiencies of the reconstructed carbons, relative to the untreated carbon.