Browsing by Author "Li, He-Jun"

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    2D ultrathin carbon nanosheets derived from interconnected Al-MOF as excellent hosts to anchor selenium for Li-Se battery
    (Elsevier, 2019-05-29) Jin, Wen-Wu; Li, He-Jun; Zou, Ji-Zhao; Inguva, Saikumar; Zhang, Qi; Zeng, Shao-Zhong; Xu, Guo-Zhong; Zeng, Xie-Rong
    Alleviating volume expansion of the electrodes and improving utilization of the active materials have become key problems restricting a successful commercialization of lithium-selenium batteries. In this paper, a 2D ultrathin carbon nanosheets derived from interconnected MOF is designed for the first time. Such carbon nanosheets are composed by parallel stacked 2D sub-units, and this unique hierarchical porous architecture is beneficial for buffering the volume expansion and for improving the utilization rate of the active materials. Therefore, the cathode displays an excellent cycling stability with a reversible capacity of 347.3 mAh g−1 at 2 C after 240 cycles.
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    Cobalt doped JUC-160 derived functional carbon superstructures with synergetic catalyst effect for Li-SeS2 batteries
    (Elsevier, 2020-07-03) Jin, Wen-Wu; Li, He-Jun; Zou, Ji-Zhao; Zhang, Qi; Inguva, Saikumar; Zeng, Shao-Zhong; Xu, Guo-Zhong; Zeng, Xie-Rong
    The carbon nanostructures with polar metal/heteroatom co-doping are considered as an effective strategy to improve their electrochemical performances. In this context, the crystal-shape engineering is carried out. Based on a new ‘‘one for six’’ strategy, the JUC-160 having a two-dimensional (2D) zeolitic imidazolate framework is transformed into six different carbon materials. These materials do not need a carbon activation process or template removal process. Instead, after a simple carbonization, a series of metal/heteroatom co-doped carbon materials with novel structures are formed. To be highlighted, this work is the first report of using self-assembled carbon nanostructures/SeS2 composites as cathode materials in the field of Li-SeS2. Moreover, those carbon nanostructures can be effectively tailored by adjusting the method of cobalt doping and the amount of cobalt dopant. Because of the benefits from the novel structures and cobalt/nitrogen co-doping, the dissolution of poly-sulfides/selenides is reduced and a high content of SeS2 (73 wt%) is achieved. The optimized cathode displays an extraordinary cycle performance with a reversible capacity of 820.87 mA h g−1 after 100 cycles, and with reversible charge-discharge efficiency is close to 100%