石墨烯包覆对H_2Ti_(12)O_(25)负极材料电化学性能影响研究

H_2Ti_(12)O_(25),作为一种新型高压负极材料,由于其循环性能好、能量密度高而逐渐引起人们的注意。本文利用湿法对负极材料H_2Ti_(12)O_(25)进行了石墨烯包覆。结果表明,石墨烯包覆能够有效的降低H_2Ti_(12)O_(25)电荷转移电阻,提高其锂离子扩散速率。H_2Ti_(12)O_(25)/graphene在1 C下的首次充电(脱锂)容量为181.6 mA·h·g~(-1)(1 C=200 m A·g-1),容量保持率为92.3%,而未包覆的H_2Ti_(12)O_(25)首次充电容量为168.5 mA·h·g~(-1),容量保持率仅为90.2%。此外,H_2Ti_(12)O_(25)/G3也表现出较好的倍率性能。

Effect of Graphene Coating on the Electrochemical Performance of H2Ti12O25Anode Materials

H2Ti12O25, as a new high-voltage anode material, has gradually attracted people's attention due to its good cycle performance and high energy density. In this paper, graphene modified H2Ti12O25 was successfully synthesized via the simple wet-coating method. The results illustrate that graphene coating layer can effectively decrease charge transfer resistance and enhance the lithium ion diffusion rate. H2Ti12O25/graphene(HTO/G3) exhibits an initial reversible capacity of 181.6 mA·h·g-1 at 1 C, and has capacity retention of 92.3% after 100 cycles at 1 C, which is higher than the uncoated H2Ti12O25 sample (168.5 mA·h·g-1, 90.2%). Besides, for H2Ti12O25/G3 sample, an enhanced rate performance is obtained.