Sol–gel synthesis of LixNi0.8Co0.2O2 via an oxalate route and its electrochemical performance as an intercalation material for lithium batteries

Abstract Li x Ni 1− y Co y O 2 solid solutions have become more important and are being intensively investigated for possible commercial utilization as a cathode material for lithium batteries. The electrochemical performance of these materials greatly depends on the synthesis route. Here, we report the low temperature sol–gel synthesis of Li x Ni 0.8 Co 0.2 O 2 ( x =1.0–1.15) using oxalic acid as a chelating agent. Solution-based synthesis of oxides has a number of advantages over conventional synthesis methods, but calcination time and temperature have always influenced electrochemical performance. We report their effects on the electrochemical performance of LiNi 0.8 Co 0.2 O 2 .The discharge capacity was 163 mAh g −1 in the first cycle and 158 mAh g −1 after 10 cycles under an optimal synthesis condition for 12 h at 800 °C. 7 Li MAS NMR studies were performed to characterize the excess lithium non-stoichiometric phases. Details of the synthesis and improved electrochemical properties are discussed.