Three-dimensional electrodes with conductive foam for electron and lithium-ion transport

Abstract

The current thickness limitations of battery electrodes are addressed. An electrode includes an electrically conductive porous foam layer, an energy-storage material in contact with the porous foam layer, and electrically conductive porous foam protrusions extending from the porous foam layer into the energy-storage material. The energy-storage material is not contained within the pores of the foam layer or the foam protrusions. These electrodes allow lithium ions (and other metal ions, if desired) to diffuse deeper into a thick energy-storage material layer, compared to conventional planar electrodes. In particular methods, fluidic foam precursors can be templated in a mold, followed by conversion into a solid conductive foam that includes the electrically conductive porous foam protrusions. The result is batteries with surprisingly high energy densities.