An exfoliation-reassembly-activation (ERA) approach to lithium-ion battery cathode fabrication is introduced, demonstrating that inactive HCoO 2 powder can be converted into a reversible Li 1-xH xCoO 2 thin-film cathode. This strategy circumvents the inherent difficulties often associated with the powder processing of the layered solids typically employed as cathode materials. The delamination of HCoO 2 via a combination of chemical and mechanical exfoliation generates a highly processable aqueous dispersion of [CoO 2] - nanosheets that is critical to the ERA approach. Following vacuum-assisted self-assembly to yield a thin-film cathode and ion exchange to activate this material, the generated cathodes exhibit excellent cyclability and discharge capacities approaching that of low-temperature-prepared LiCoO 2 (~83 mAh g -1), with this good electrochemical performance attributable to the high degree of order in the reassembled cathode. HCoO 2 powder is successfully exfoliated in water to yield solution-processable aqueous dispersions of [CoO 2] - nanosheets, which are reassembled into self-supporting thin films. Ion exchange with lithium generates Li 1-x H x CoO 2 thin films that can be used as reversible cathodes with excellent cyclability and discharge capacities approaching that of low-temperature-prepared LiCoO 2.
ASJC Scopus subject areas
- Materials Science(all)