Browsing by Author "Zeng, Xie-Rong"

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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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    Al-based MOF derived self-assembled carbon nanosheets as innovative anodes for Li-and Na-ion batteries
    (IOP, 2019-12-20) Zeng, Xie-Rong; Wenwu, Jin; Li, Hejun; Saikumar, Inguva; Zhang, Qi; Shaozhong, Zeng; Guozhong, Xu; Zou, Jizhao
    Functional modification and structural design of carbon electrode materials are considered as a cost-effective method to improve their electrochemical performance. In this study, a solvothermal method is applied to realize self-assembly of the metal-organic framework. After simple carbonization and acid treatment, carbon nanosheets with 2D adjustable defective sub-units are successfully prepared for the first time. It is found that carbonization temperature has a significant effect on the carbon skeleton structure. The optimal nanostructures with large specific surface area and appropriate pore size distribution make self-assembled carbon nanosheets having excellent Li/Na- ion storage properties. In addition, the adjustable carbon skeleton structure can effectively avoid irreversible damage when charge-discharge cycles. For Li-ion batteries, a specific capacity of 825 mAh g−1 is achieved after 100 cycles at 0.1 C, while for Na-ion batteries a specific capacity of 193 mAh g−1 is observed after 100 cycles at 0.5 C. Moreover, for Na-ion batteries, even at a high rate of 5 C the material delivers a specific capacity of 109.5 mAh g−1 after 3500 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%