Rational design of stable 4 V lithium ion capacitor
Rational design of stable 4 V lithium ion capacitor
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DOI：
10.1016/j.nanoen.2016.07.018
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发表时间：
2016-09
期刊：
影响因子：
17.6
通讯作者：
Wee Siang Vincent Lee;Erwin Peng;Meng Li;Xiaolei Huang;J. Xue
中科院分区：
文献类型：
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作者：
Wee Siang Vincent Lee;Erwin Peng;Meng Li;Xiaolei Huang;J. Xue
锂离子电容器（LIC）已经成为协同联合收割机低电位锂离子电池电极与高电位超级电容器电极的令人兴奋的方法。尽管通过这种耦合可以实现宽的电池电势窗口，但是由于石墨结构的存在引起的电解质降解问题，当前的LIC继续在故意收缩的电池电势窗口（2- 3V）下操作。在此，具有高能量和功率密度的高度稳定的4V LIC被合理地设计为具有3D非晶碳正极，其与石墨碳相比表现出对高电压的优异耐受性。组装后的4 V LIC与高容量MnFe 2 O 4/碳负极结合，在2 A g−1下循环6000次后表现出86.5%的显著容量保持率，库仑效率约为100%（表明电解质分解最小），同时在200 W kg−1的功率密度下实现157 W h kg− 1的高能量密度。这项工作表明，采用无定形碳相比，更多的石墨碳作为正极的优势，因此，作为一个指导原则，设计稳定的4 V LIC与无定形碳。
Li ion capacitor (LIC) has emerged as an exciting approach to synergistically combine low potential Li ion battery electrode with high potential supercapacitor electrode. Although wide cell potential window can be achieved through such coupling, current LICs continue to operate at a deliberately constricted cell potential window (2–3 V) due to electrolyte degradation concerns caused by the presence of graphitic structure. Herein, highly stable 4 V LIC with high energy and power density was rationally designed with 3D amorphous carbon positive electrode which demonstrated exceptional tolerance to high voltage as compared to graphitic carbon. The as-assembled 4 V LIC, coupled with high capacity MnFe2O4/carbon negative electrode, exhibited remarkable capacity retention of 86.5% after cycling for 6000 cycles at 2 A g−1, withca.100% coulombic efficiency (indicating minimal electrolyte decomposition), while achieving high energy density of 157 W h kg−1at power density of 200 W kg−1. This work demonstrates the advantages of employing amorphous carbon as compared to more graphitic carbon as positive electrode and thus, serves as a guideline for designing stable 4 V LIC with amorphous carbon.