A novel electrode for a battery is provided. The electrode may contain active material nanoparticles embedded in a solid polymer electrolyte. The electrolyte can also act as a binder for the nanoparticles. A plurality of voids is dispersed throughout the solid polymer electrolyte. The electrode may also contain electronically conductive carbon particles. Upon charging or discharging of the cell, the nanoparticles expand as they take up active material ions. The solid polymer electrolyte can deform reversibly in response to the expansion of the nanoparticles and transfer the volume expansion to the voids.