Browsing by Author "Li, Xin"

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    Effects of nanobubble water on digestate soaking hydrolysis of rice straw
    (Elsevier, 2024-05-24) Wang, Enzhen; Xing, Fan; Chen, Penghui; Zheng, Yonghui; Lyu, Tao; Li, Xin; Xiong, Wei; Li, Gang; Dong, Renjie; Guo, Jianbin
    This study investigated the performance of combined nanobubble water (NW) and digestate in the soaking hydrolysis process. Two types of NW (CO2NW and O2NW) with digestate were used to soak rice straw for 1, 2, 3, 5, and 7 days. During soaking process, the volatile fatty acids (VFA) concentration in the treatment with O2NW and digestate for 3 days (O2NW-3 d) reached 7179.5 mg-HAc/L. Moreover, the highest specific methane yield (SMY) obtained in this treatment could reach 336.7 NmL/gVS. Although the addition of NW did not significantly increase SMY from digestate soaking, NW could accelerate the rate of methane production and reduce digestion time of T80. The enrichment of Enterobacter in the soaking process was observed when using CO2NW and O2NW as soaking solutions which played important roles in VFA production. This study provides a new insight into environment-friendly enhanced crop straw pretreatment, combining NW and digestate soaking hydrolysis.
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    High performance rechargeable aluminium ion batteries enabled by full utilization and understanding of polyaniline cathodes
    (Elsevier, 2024-07-08) Wei, Guokang; Qiao, Jia; Li, Xin; Tao, Fei; Xue, Weixi; Hu, Sijiang; Luo, Zhenhua; Yang, Jianhong
    As a renowned conductive polymer, polyaniline (PANI) shows remarkable potential in organic cathode materials for rechargeable aluminium ion batteries (RAIBs). However, existing research has not given sufficient understanding and explanation of the structure and states of PANI but failed to achieve ideal electrochemical performance. In this study, we differentiate and investigate for the first time its primary-doped (PANI-1), re-doped (PANI-Re), secondary-doped (PANI-2), and emeraldine based (PANI-EB) forms, meanwhile attempt to enhance the conductivity of PANI-EB using multi-walled carbon nanotubes (PANI-EB@C). Among them, the high-doped PANI-2 and non-doped PANI-EB exhibit theoretical capacity utilization far superior to lower doped PANI-1 and PANI-Re, with both specific capacities reaching approximately 225 mAh/g (full capacity utilization rate of 76.53 %) at a current density of 1 A/g, while maintaining capacity retention rates of 92.89 % after 2000 cycles and 92.44 % after 5000 cycles, respectively. Furthermore, the high-conductivity PANI-EB@C displays a discharge specific capacity of 284 mAh/g (full capacity utilization rate of 96.59 %), with a capacity retention rate of 91.19 % after 5000 cycles. Electrochemical analysis, Gaussian theoretical calculations, ex-situ characterization collectively indicate that the electrochemical performance of doped PANI is positively correlated with the degree of doping-induced conductivity changes, while the unique internal redox process of PANI-EB enhances the release of performance and could be further optimized by the assistant of conductivity medium. This work advances the classification of the electrochemical performance and structural understanding of PANI cathode materials to an extremely high stage, towards the practical application of a low-cost, high-performance, sustainable, and green cathode material in large-scale energy storage devices.
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    Process mechanisms of nanobubble technology enhanced hydrolytic acidification of anaerobic digestion of lignocellulosic biomass
    (Elsevier, 2023-12-21) Zhu, Yali; Lyu, Tao; Li, Daoyu; Zhang, Zongqin; Guo, Jianbin; Li, Xin; Xiong, Wei; Dong, Renjie; Wang, Siqi
    This study explored the efficiency of CO2-, N2-, and H2- nanobubble treatment in anaerobic digestion (AD) of rice straw, with a focus on the processes and metabolic pathways of hydrolytic acidification, and revealed the underlying mechanisms. Mechanistic investigations revealed that nanobubbles, particularly CO2 nanobubbles, significantly increased the degradation of amorphous cellulose, resulting in higher levels of soluble carbohydrates (6.27 % – 11.13 %), VFAs (4.39 % – 24.50 %), and a remarkable cumulative H2 yield (74 – 94 times) Microbial community analysis indicated that the CO2 nanobubble promoted the growth of acidifying bacterial communities, such as Mobilitalea, unclassified_f_Lachnospiraceae, and Bacteroides. This indicates that the introduction of CO2 nanobubbles improved the total abundance of predicted functional enzymes were increased by 14 %, resulting in the production of more easily degradable intermediates. Based on the analysis of total methane production and kinetic analysis, it can be concluded that nanobubble addition enhanced methane production levels of 4.22 %−7.79 % with lower lag time (λ) (0.88–1.06 day) compared to the control group (1.09 day). The results also elucidated changes in relative enzymatic activities involved in the bioconversion of cellulose and hemicellulose during the hydrolysis stage with nanobubble treatment. This work is more beneficial for understanding the promoting effect and mechanism of nanobubbles on AD, facilitating the more precise application of nanobubble technology in the field of renewable energy.
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    Spatial reticulate polytriphenylamine cathode material with enhanced capacity for rechargeable aluminum ion batteries
    (Springer, 2023-07-03) Tao, Fei; Wei, Guokang; Xu, Xinqi; Xu, Weize; Xie, Wei; Yang, Jianhong; Luo, Zhenhua; Li, Xin; Qiao, Jia
    Rechargeable aluminum ion batteries (RAIBs) are a very attractive option for large-scale energy storage thanks to their promising theoretical capacity, high energy density, low cost, abundant earth resources, and environmental friendliness. While the cathode materials chosen and prepared are so essential for the electrochemical performance of RAIBs that extensive efforts and research have been done. In this study, the electrochemical performances of RAIBs were optimally improved by the chemical polymerization of triphenylamine to obtain polytriphenylamine (PTPAn) as the cathode material. The polymerization process improved the spatial reticulate structure of triphenylamine, gained a three-dimensional mesh-like nanostructure, which provided more chemical reaction sites and ion reaction channels, greatly increased the specific surface area, and accelerated the electrochemical reaction kinetics. On this basis, a stable discharge-specific capacity of around 137.4 mAh g−1 was achieved at high current densities of 1 A g−1 for the PTPAn cathode, and the Coulombic efficiency was maintained at about 99% after the life of 500 cycles. The understanding and appreciation of the charging and discharging working principle of PTPAn material as RAIBs cathode, meantime, were deepened by a multitude of ex-situ experiments. These findings are anticipated to serve as the cornerstone for the subsequent development of large-scale RAIBs systems for energy storage that use organic polymers as the cathode material.