Microstructured pebble stone like Ni-NiO composite as anode of high-performance lithium-ion batteries

Ni-NiO electrodes were synthesized via thermal oxidation of pure nickel powder and evaluated as anode of lithium-ion batteries (LIBs). The composite synthesized at 600˚C, 800˚C, and 1000˚C exhibited nanochips, crushed gravel stone, and pebble stone-like morphology, respectively. The nanochips- and crushed gravel stone featured-like electrodes exhibited erratic behavior, and specific capacity faded rapidly from 754.49 mAh g-1 and 101.12 mAh g-1 to 464.04 mAh g-1 and 9.55 mAh g-1, respectively over 10th cycle at a current rate of 1C as the electrode experiences internal short circuit. The pebble stone-like Ni-NiO electrode exhibited improved and stable cyclic performance with 1st discharge capacity of 365.17 mAh g-1 and reduced to 67.42 mAh g-1 even after 40th cycle at 1C current rate. The improved electrochemical performance of composite Ni-NiO with a pebble stone-like feature can be attributed to the mechanical stability of the electrode, which can buffer volume expansion, and the presence of more nanoparticles on the electrode surface allows more interaction with Li+.