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