Pulsed laser deposited NiO–NiSe nanocomposite as a new anode material for lithium storage

• We successfully fabricated NiO–NiSe composite thin films by pulsed laser deposition method.
• The NiO–NiSe composite electrode shows significantly improvement in cycling performance than single phase electrode.
• Electrochemical mechanism of NiO–NiSe electrode with lithium was revealed.

NiO–NiSe nanocomposite thin films are successfully fabricated by pulsed laser deposition (PLD) method and electrochemical properties of this composite are investigated by cyclic voltammetry and discharge/charge measurements. NiO–NiSe composite electrode delivers an initial discharge capacity of 577.7 mAh·g−1 and retains reversible capacity of 495 mAh·g−1 after 50 cycles, which exhibits significant improvement in cycling stability when compared with NiO thin film electrode. The electrochemical reaction mechanism of NiO–NiSe with lithium is examined by high-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED) techniques. The decomposition reactions of NiO–NiSe with Li to form metal Ni, Li2O and possible small nanosized Li2Se during discharge process, and the reformation of NiO–NiSe nanocomposite after charge process are revealed.