摘要
以嵌锂过渡金属氧化物(锂盐)和双电层储能材料活性炭(AC)为电极活性物质,制备LiMn_2O_4-AC||AC、LiFePO_4-AC||AC、LiMn_2O_4-AC|Li_4Ti_5O_(12)-AC、LiFePO_4-AC||Li_4Ti_5O_(12)-AC电池-电容器。通过恒电流充放电、循环伏安以及交流阻抗等对其电化学性能进行研究。结果显示:电池-电容器在低工作电压段,电荷主要以双电层储能形式存储于活性炭电极;在高工作电压段电荷主要以锂离子插嵌-脱嵌形式存储于嵌锂过渡金属氧化物。锂盐和AC结合可以有效提高电池-电容器的工作电压、能量密度,同时又具有较好的功率特性。其中LiFePO_4-AC|Li_4Ti_5O_(12)-AC具有较好的综合电化学性能,当电压为3.2 V时,能量密度为124.6 Wh·kg^(–1),功率密度为461.7 W·kg^(–1),内阻为2.2?,充放电效率为93.1%。
Capacitor-batteries of LiMn204-AC｜｜AC, LiFePO4-AC｜｜AC, LiMn204-AC｜｜Li4TisO12-AC and LiFePO4-AC｜｜ Li4Ti5012-AC were constructed via internal combination of lithium salts and activated carbon （AC） as the electrode activated materials. The electrochemical performance of capacitor-battery was investigated by the constant current charge-discharge testing, cyclic voltammetry analysis and alternating current impedance technique. Ions were stored on the surface of AC at the low potential stage, however, ions were stored in the lithium salts at the high potential stage. The results show that the energy density of capacitor-battery is improved significantly by using the combination of lithium salts and activated carbon as the electrode activated materials, at the same time the capacitor-battery also has high power density. LiFePO4-AC｜｜Li4TiSO12-AC electrode capacitor-battery exhibits better electrochemical performance： energy density is 124.6 Wh · kg-1, power density is 461.7 W · kg-l, resistance is 2.2Ω, and charge-discharge efficiency is 93.1% at 3.2 V working potential.
出处
《电子元件与材料》
CAS
CSCD
2016年第9期64-69,共6页
Electronic Components And Materials
基金
国家高技术研究发展计划项目(863计划)(No.2012AA110302)
国家自然科学基金项目(No.21206083)
辽宁省大学生创新创业训练计划项目(No.201510167000006,No.201510167000019)
关键词
电池
电容器
锂盐
活性炭
内结合
电化学性能
battery
, capacitor
lithium salts
activated carbon
internal combination
electrochemical performance
