Hundred-micron-sized all-solid-state Li secondary battery arrays embedded in a Si substrate

Fabrication and charge/discharge behaviors of all-solid-state Li secondary battery arrays embedded into three Si trenches of 200x100 mum(2) in area and 0.5similar to2.0 mum in depth are presented. The battery arrays in a Si wafer, consisting of multiple layers (Al current collector/Li/SiO2-15 at. % P2O5/LiMn2O4/polycrystalline silicon current collector), are prepared by combining a sol-gel spin-coating method and Si very-large-scale integration technologies. Porous spin-on glass (SiO2-15 at. % P2O5) is adopted as an electrolyte layer, in which spatial paths for Li+ ions are artificially introduced into the glass. Each active battery area is isolated with double insulating walls (Si3N4/SiO2). The battery arrays demonstrate a constant capacity of similar to9.2 muA h cm(-2) at similar to3.6 V up to 100 cycles. (C) 2002 American Institute of Physics.