are generated at the negative electrode 102 because there is extraction via oxidation of lithium ions from the lithium 116 plated on the nanowires 114 of the negative electrode 102 and the electrons are consumed at the positive electrode 104 because metal cations or sulfur ions change oxidation state in the positive electrode 104 during charging the reactions are reversed with lithium and electrons moving in the direction of the arrow 138 as lithium ions are inserted into the active portion 122 the volume of the active portion 122 increases as the volume of the active portion 122 increases the pressure within the positive electrode 104 increases the increased pressure in the positive electrode 104 in embodiments incorporating a fluid such as a fluid electrolyte causes the fluid to flow toward the negative electrode 102 because the nanowires 114 do not fill the entire negative electrode 102 the fluid can flow into the negative electrode 102 the rigid support walls 110 and 112 thus provide an expansion volume within the negative electrode 102 additionally the rigidity of the support structures 110 and 112 protects the active material in the electrode 102 from the volume change in the positive electrode 104 as lithium plates onto the nanowires 114 the lithium 116 may plate predominantly in directions toward another nanowire 114 specifically since one side of the rigid wall 110 is mounted to the current collector 108 lithium will not plate onto that surface portion thus plating of lithium on the support wall 110 occurs predominantly on the sides of the nanowires 114 facing other nanowires 114 within the support wall 110 or nanowires.