Transition metal oxides (TMO) with commendable theoretical capacity resulted from the conversion reaction have been studied extensively as anode material for Li-ion batteries. The major limitations of TMO are low electrical conductivity and large volume change about 174 % during cycling reaction. This can be overcome by modifying the morphology of the active material. Different morphological nano and micro structures have been synthesized by various synthetic procedures. CuO, a prominent TMO, has been explored by many researchers due to its high theoretical capacity, less toxicity and easy availability.

 In the current investigation, different morphological CuO have been synthesized by rapid hydrothermal and precipitation method. Physical characterizations are carried out viz., XRD, FESEM, TEM, FT-IR, and XPS techniques. Electrochemical cycling performance of the synthesized CuO of different morphologies have been evaluated as anode material for Li-ion batteries at different current densities between 215 mA g^-1 and 4.3 A g^-1. CuO of nano hexagonal morphology obtained from hydrothermal synthesis exhibits stable discharge performance of ~575 mAh g^-1 at current density of 215 mA g^-1 with low irreversible capacity of 265 mAh g^-1 in the first cycle. This resultant value is comparably lower than several reported values obtained from different nano morphological CuO and composites of CuO with conducting additives, establishing  it as a superoir  anode material for lithium ion batteries. Nano CuO anode exhibits high rate capability up to the current density of 4.3 A g^-1_, resumes the initial capacity of 572 mAh g^-1  even after 100 cycles and remains stable with zero capacity fading at 215 mA g^-1 current density. While CuO microballs synthesized via precipitation method delivers charge and discharge capacity of 860 mAh g^-1 and 372 mAh g^-1 during first cycle respectively at the current density of 215 mA g^-1. Further, the capacity fading increases upon cycling and delivers 276 mAh g^-1 after 30 cycle. Ex-situ FESEM analysis clearly inidicates that the morphology change during lithiation and delithiation reaction is responsible for the varying cycling performance. CuO nano hexagons form an integrated network thereby enhancing the electrical conductivity for better electrochemical performance. In the case of CuO microballs, the disconnected microstructure formed during cycling due to the volume change causes electrode disintegration and poor electrochemical performance at higher current rate.