Wang Chong, Zhan Changzhen, Ren Xiaolong, Lv Ruitao, Shen Wanci, Kang Feiyu, Huang Zheng-Hong
State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University Beijing 100084 P. R. China
Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University Beijing 100084 China.
RSC Adv. 2019 Dec 20;9(72):42316-42323. doi: 10.1039/c9ra09411c. eCollection 2019 Dec 18.
Lithium ion capacitors (LICs), bridging the advantages of batteries and electrochemical capacitors, are regarded as one of the most promising energy storage devices. Nevertheless, it is always limited by the anodes that accompany with low capacity and poor rate performance. Here, we develop a versatile and scalable method including ball-milling and pyrolysis to synthesize exfoliated MoS supported by N-doped carbon matrix derived from chitosan, which is encapsulated by pitch-derived carbon shells (MoS/CP). Because the carbon matrix with high nitrogen content can improve the electron conductivity, the robust carbon shells can suppress the volume expansion during cycles, and the sufficient exfoliation of lamellar MoS can reduce the ions transfer paths, the MoS/CP electrode delivers high specific capacity (530 mA h g at 100 mA g), remarkable rate capability (230 mA h g at 10 A g) and superior cycle performance (73% retention after 250 cycles). Thereby, the LICs, composed of MoS/CP as the anode and commercial activated carbon (21 KS) as the cathode, exhibit high power density of 35.81 kW kg at 19.86 W h kg and high energy density of 87.74 W h kg at 0.253 kW kg.
锂离子电容器（LICs）兼具电池和电化学电容器的优点，被视为最有前景的储能装置之一。然而，它始终受到阳极的限制，阳极存在容量低和倍率性能差的问题。在此，我们开发了一种通用且可扩展的方法，包括球磨和热解，以合成由壳聚糖衍生的氮掺杂碳基质负载的剥离型MoS，并由沥青衍生的碳壳包裹（MoS/CP）。由于高氮含量的碳基质可以提高电子导电性，坚固的碳壳可以抑制循环过程中的体积膨胀，并且层状MoS的充分剥离可以减少离子传输路径，MoS/CP电极具有高比容量（在100 mA g时为530 mA h g）、出色的倍率性能（在10 A g时为230 mA h g）和优异的循环性能（250次循环后保持率为73%）。因此，由MoS/CP作为阳极和商业活性炭（21 KS）作为阴极组成的LICs，在19.86 W h kg时具有35.81 kW kg的高功率密度，在0.253 kW kg时具有87.74 W h kg的高能量密度。
