The use of nanoporous anodic alumina as a template for silicon nanowire growth enables the production of ultra dense nanowire arrays with density up to 8.109cm(-2). The integration of such nanowire arrays in micro-supercapacitor electrodes significantly improves the electrode capacitance per planar surface area and nanowires length unit compared to electrodes made from silicon nanowires grown from gold colloids (from 5.2 mu F.cm(-2).mu m to 36.7 mu F.cm(-2).mu m). Micro-supercapacitors with such electrodes and ionic liquid as electrolyte have a very promising cycling stability featuring less than 1% of losses after 300000 cycles. (C) 2013 Elsevier Ltd. All rights reserved.