Promoting the energy density of lithium-ion capacitor by coupling the pore-size and nitrogen content in capacitive carbon cathode

JOURNAL OF POWER SOURCES

卷:498

Article

Dai, Xuan¹  Lei, Shulai²  Liu, Juan^3,4  Shang, Zhitong¹  Zhong, Shengwen¹  Li, Xiaocheng¹ 

[1] Jiangxi Univ Sci & Technol, Fac Mat Met & Chem, Jiangxi Prov Key Lab Power Battery & Mat, Ganzhou 341000, Peoples R China

[2] Hubei Univ Arts & Sci, Hubei Key Lab Low Dimens Optoelect Mat & Devices, Xiangyang 441053, Peoples R China

[3] Jiangxi Univ Sci & Technol, Sch Resources & Environm Engn, Ganzhou 341000, Peoples R China

[4] Changzhou Inst Technol, Sch Chem Engn & Mat, Changzhou 213000, Peoples R China

关键词: Lithium-ion capacitor;    Carbon material;    Pore size;    Solvated PF6 ions;    Nitrogen-doped;   

DOI  :  10.1016/j.jpowsour.2021.229912

来源: Elsevier

【 摘 要 】

The mediocre capacitive performance of carbon cathode has seriously hampered the advancement of lithium ion capacitors (LICs). The guideline for high-performance capacitive carbon cathode is still lacking. In this study, the desired microstructure of carbon cathode that suitable for LiPF6-contained electrolyte is calculated by using density functional theory. Results suggest that only the pore sizes more than 2.18 nm can accommodate the solvated PF6- ions. Experimental results confirm that the capacitive performance of the synthesized activated polyaniline-derived carbon (APDC) can be significantly promoted as the pore size was more than 2 nm. Especially, the APDC-700-based electrode demonstrates outstanding electrochemical performance with high capacitance (247 F g(-1) at 0.1 A g(-1)) and good rate capability (156 F g(-1) at 10 A g(-1)), owing to the appropriate pore size and high N content in carbon matrix. The APDC-700-based LIC device can deliver an ultra-high energy density of 300.3 Wh kg(-1) at 318 W kg(-1), as well as good cycling stability over 10 000 cycles. This well-designed work will be conducive to deeply understand the performance improvement of capacitive carbon cathode in LiPF6 electrolyte and provides guidelines for designing advanced LIC devices.

【 授权许可】

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