A Novel Structure and Cycle Performance of C03O4-C prepared by Electro-codepositing as Negative Electrode for Lithium-ion Batteries

摘要

Co_3O_4-C negative electrode for lithium-ion batteries has been prepared by electro-codepositing in 0.5mol/L Co(NO_3)_2+C solutions and sintering under O.latm vacuum at 245°C. Without carbon in the film, it has a 20～30 nm thick layer of Co_3O_4 with a beehive-like structure. When the film contains 10.84% of carbon, it also has a beehive-like structure that consists of composite Co_3O_4-C particles. When the film contains 32.76% of carbon, it was made up of some bulky carbon with Co_3O_4-C all around and a part of porous beehive with Co_3O_4-C composite needles inside. When the Co_3O_4-C and Li are assembled to simulative batteries, charged and discharged at 0.2C, film contains 32.76% of carbon has the best cycle performance, after charged/recharged 230 cycles, the charge specific capacity was 669.8 rnAh·g-1, and the holding ratio was 100%; after charged/recharged 260 cycles, the charge specific capacity was decreased to 505.3 mAh·g-1, it still keeps partial beehive-like structure.