基于离子凝胶电解质的TiO_(2)(B)@C/CNT//AC准固态锂离子电容器

Ionogel electrolyte based TiO_(2)(B)@C/CNT//AC quasi-solid-state lithium-ion capacitors

以微波辅助溶剂热法制备多壁碳纳米管负载的碳包覆单斜相二氧化钛纳米复合电极,通过静电纺丝技术制备聚酰亚胺纤维膜,进而制备三元离子凝胶电解质,最后与商业活性炭组装成新型准固态锂离子电容器。结果表明,TiO_(2)(B)@C/CNT纳米复合电极呈现出高可逆容量(291 m Ah/g)和高电化学反应动力学特性。PI/[EMIM][BF_(4)]/Li TFSI离子凝胶电解质呈现出高离子电导率和电化学稳定性,其可将锂离子电容器的工作电压拓展至3.8 V。由于电解质中存在离子液体,器件的电化学性能呈现出明显的温度依赖性。准固态锂离子电容器在60℃时最大能量密度和最大功率密度分别为83.1 Wh/kg和18338.1 W/kg。

Lithium-ion capacitors(LICs) are attracting extensive attentions owing to their high energy density, rapid power output, and excellent cyclability. However, one of the key challenges encountered by LICs is balancing the sluggish kinetics of intercalation electrodes against capacitive electrodes. In this work, a Ti O2(B)@C/CNT nanohybrid electrode was synthetized by a microwave-assisted solvothermal method. The nanohybrids exhibited a high reversible capacity of 291 m Ah/g and high kinetic characteristics. Subsequently, a polyimide(PI) membrane was prepared by electrospinning technique for the construction of a ternary ionogel electrolyte. The ionogel electrolyte exhibited high ionic conductivity and electrochemical stability. Notably, a quasi-solid-state lithium-ion capacitor(QSLIC) was assembled with TiO_(2)(B)@C/CNT as anode, commercial activated carbon(AC) as cathode and the ionogel electrolyte. It delivered a maximum energy density of 83.1 Wh/kg and a maximum power density of 18338.1 W/kg at 60℃. Moreover, the electrochemical performances of the QSLIC exhibited an obvious temperature dependence.