Favorable binding effect for improving the electrochemical performance of cobalt oxide anode for lithium ion batteries

Electrochemical characteristics of CoO anode are highly dependent on the use of binders. Its electrochemical reversibility is drastically improved by using poly(acrylic acid) (PAA) as a binder in comparison with the commonly used poly(vinylidene fluoride) (PVdF) binder. PAA can effectively buffer the volume expansion of the CoO electrode during the lithium insertion and extraction, resulting in improving electrochemical characteristics of the electrode. The cyclic stability of CoO electrode with PAA binder is remarkably improved. Impedance of CoO electrode with PAA binder is much smaller than that of PVdF binder. Moreover, the reversible capacity reaches 860 mA h g−1 at a current density of 50 mA g−1.