3D porous hierarchical Li2FeSiO4/C for rechargeable lithium batteries

Abstract

Lithium iron silicates (Li₂FeSiO₄) are promising cathodes for rechargeable lithium batteries owing to their high capacity, low cost, and superior stability. However, Li₂FeSiO₄ suffers from extremely low electronic and ionic conductivity. Herein, we used a two-step method to fabricate carbon-painted, three-dimensional (3D) porous hierarchical Li₂FeSiO₄ (3D Li₂FeSiO₄/C) as an efficient cathode, based on a facile hydrothermal reaction followed by carbon nanopainting. The hierarchical porous structure endows the Li₂FeSiO₄/C with efficient electrolyte storage and penetration, whereas the 3D carbon nanopainting provides an expressway for rapid electron transport. As a result, this 3D Li₂FeSiO₄/C exhibits a high electrochemical activity towards Li cycling, outperforming its counterpart without carbon painting and other Li₂FeSiO₄ materials. This research highlights the potential of engineering 3D porous structure to circumvent the poor conductivity in battery materials.