The remaining LO (in the cathode material) was recovered (0.1-0.2 g per treatment) and added to a 23 ml teflon container in a Parr hydrothermal vessel containing 10 ml 0.5-1M NaOH. The hydrothermal vessel was heated overnight at 160°C for 2-12 hours to form the layered metal hydroxide, M(OH)2 (where M = Ni, Co, Mn and Al), and decompose the PVDF binder. The resulting powder was filtered, washed and dried. The recovered hydroxide powder was heated (450°C/12h/air followed by 850°C/12h/O2) with LiOH•H2O to resynthesise the LO.