文摘
Co<sub>2sub>(OH)<sub>2sub>CO<sub>3sub> nanosheets were prepared and initially tested as anode materials for Li ion batteries. Benefiting from hydroxide and carbonate, the as-prepared sample delivered a high reversible capacity of 800 mAh g<sup>鈥?sup> after 200 cycles at 200 mA g<sup>鈥?sup> and long-cycling capability of 400 mAh g<sup>鈥?sup> even at 1 A g<sup>鈥?sup>. Annealed in Ar, monoclinic Co<sub>2sub>(OH)<sub>2sub>CO<sub>3sub> nanosheets were transformed into cubic CoO nanonets with rich pores. The pore size had apparent influence on the high-rate performances of CoO. CoO with appropriate pore sizes exhibited greatly enhanced Li storage performances, stable capacity of 637 mAh g<sup>鈥?sup> until 200 cycles at 1 A g<sup>鈥?sup>. More importantly, after many fast charge鈥揹ischarge cycles, the highly porous nanonets were still maintained. Our results indicate that Co<sub>2sub>(OH)<sub>2sub>CO<sub>3sub> nanosheets and highly porous CoO nanonets are both promising candidate anode materials for high-performance Li ion batteries.