In this work we report a lithium ion battery based on a nanostructured Sn-C anode, an improved lithium iron phosphate. LiFePO4, cathode and a polyethylene oxide-based electrolyte. The battery has a solid-like configuration, high safety and can operate at room temperature with a stable capacity of the order of 120 mAh g(-1) at a voltage of 2.8 V. These properties candidate the battery as very appealing energy accumulation system suitable for environmentally friendly, safe, applications. (C) 2011 Elsevier B.V. All rights reserved.