摘要
以葡萄糖为碳源,以Li_2CO_3、TiO_2为原料,采用原位复合法制得不同碳质量分数的锂离子电池复合负极材料Li_4Ti_5O_（12）-C。通过X射线衍射和扫描电子显微镜对复合材料的结构及表面形貌进行了表征,采用恒流充放电和电化学阻抗等技术对复合材料进行电化学性能测试。结果表明：Li_4Ti_5O_（12）-C没有杂相,颗粒均匀。其中,碳质量分数为3%的复合材料在0.5 C下的首次放电比容量最高,为185.9 mA·h/g,循环50次后,其放电比容量仍为161.5 mA·h/g,容量保持率为86.9%;在4.0 C下,其首次放电比容量为106.9mA·h/g。与其他样品相比,碳质量分数为3%的复合材料循环伏安氧化还原峰电位相差为278.6 mV,溶液阻抗为6.198？,电荷转移电阻为187.2？,电化学性能最好。
Li_4Ti_5O_（12）-C with different mass fractions of carbon were prepared by in-situ composite method using glucose as carbon sources, Li2 CO3 and Ti O2 as staring materials. The structure and surface morphology of the prepared composite materials were characterized by X-ray diffraction（XRD） and scanning electron microscope（SEM）. The electrochemical performances were investigated using constant-current chargedischarge and electrochemical impedance spectroscopy（EIS）. The results showed that the synthesized Li_4Ti_5O_（12）-C composite particles were homogeneous without impure phase. Among these samples, Li_4Ti_5O_（12） with 3% mass fraction of carbon showed the highest first discharge capacity of 185.9 m A·h/g when discharging at 0.5 C rate, and the specific capacity remained 161.5 m A·h/g after 50 cycles with a capacity retention of 86.9%. However, the first specific discharge capacity was 106.9 m A·h/g when discharging at 4.0 C rate. Compared with the other samples, Li_4Ti_5O_（12） with 3% mass fraction of carbon gave the smallest potential difference of 278.6 m V between the oxidation and reduction reaction. Its solution impedance was 6.198 ？, and charge transfer resistance was 187.2 ？. Li_4Ti_5O_（12） with 3% mass fraction of carbon exhibited the best electrochemical performances.
作者
于小林
吴显明
丁心雄
李叶华
刘立瑶
吴贤钊
石青锋
YU Xiao-lin;WU Xian-ming;DING Xin-xiong;LI Ye-hua;LIU Li-yao;WU Xian-zhao;SHI Qing-feng(College of Chemistry and Chemical Engineering, Jishou University, Jishou 416000, Hunan, China;Xiangxi Minerals and New Materials Development and Service Center, Jishou 416000, Hunan, China)
出处
《精细化工》
EI
CAS
CSCD
北大核心
2018年第7期1216-1220,共5页
Fine Chemicals
基金
国家自然科学基金(21263004,51762016)
吉首大学研究生校级科研项目(Jdy16017)
吉首大学化学化工学院研究生专项科研课题
“锰锌钒产业技术”协同创新中心研究生科研创新课题~~
关键词
锂离子电池
LI4TI5O12
表面修饰
电化学
原位复合法
有机电化学与工业
lithium-ion batteries
Li_4Ti_5O_（12）
surface modification
electrochemistry
in situ composite method
electro-organic chemistry and industry
