The preparation, performance and lithiation mechanism of cobalt-doped zinc oxide as a high performance anode material for LIB

Zn1-xCoxO (0 ≤ x ≤ 0.15) anode material was prepared by an easy polyacrylamide assisted sol-gel route. The successful replacement of Zinc by Cobalt within Cobalt content x ≤ 0.09 was confirmed by structural characterization. The introduction of Cobalt element greatly improved the electro-chemical performances of the matrix Zinc oxide. Without carbon coating, at the 20th cycle, Zn0.91Co0.09O anode still preserved a capacity a little bit more than 1000 mA h g−1 and a capacity more than 600 mA h g−1 was retained at the end of the 50th cycle. Better rate capability was also witnessed. The SEM, EIS at OCV, CV and in situ XRD were further carried out to elucidate the lithiation mechanism. The role Cobalt doping played can be summarized as follows: the stabilization of the Li2Zn phase, the minimization of charge transfer resistance and the enhanced reversibility of the reduction from metal oxide to metal.