Enhanced Li storage properties of nickel oxalate microtubes with manganese doping and graphene oxide for lithium-ion batteries

Nowadays, metal oxalates with high discharge/charge capacities were chosen as new anode materials for batteries. Here, novel nickel oxalates microtubes with manganese doping and graphene Oxide (Ni0.8Mn0.2C2O4∙2 H2O/GO) are synthesized at low temperature through a facile microwave-assisted solvothermal method. The X-ray diffraction confirmed a formation of a pure binary compound of Ni0.8Mn0.2C2O4∙2 H2O/GO without contamination by other compounds of Nickel or Manganese. Furthermore, the formed product shows a good crystallinity and has a high surface area of 24.3 m2 g−1. With the assistance of graphene, the material delivers a high discharge capacity of 1781 mA h g−1. Even at high current densities of 5.0 and 10.0 A g−1, discharge capacities of 1138.1 and 891.0 mA h g−1 can be obtained. Encouraged by the superior rate performance, the long-term cycling performance at 10 A g−1 and 20 A g−1 was tested showing a discharge of 676.6 mA h g−1 after 300 cycles and 346.4 mA h g−1 after 1000 cycles. The remarkable electrochemical performance can be attributed to the doping of Mn in the structure of NiC2O4 ∙2 H2O and the contribution of graphene.