Lithium-sulfur(Li-S)batteries have been regarded as promising next-generation energy-storage devices owing to their inherently high theoretical energy density.Unfortunately,the poor capacity and cycling life caused by...Lithium-sulfur(Li-S)batteries have been regarded as promising next-generation energy-storage devices owing to their inherently high theoretical energy density.Unfortunately,the poor capacity and cycling life caused by severe polysulfide shuttle effect and sluggish redox kinetics in sulfur cathodes greatly impede the practical application of Li-S batteries.Herein,a new class of nanonetworkstructured carbon decorated with oxygen-vacancy-containing cerium oxide nanoparticles(NSC-CeO_(2−x)),in which carbon skeleton is composed of highly conductive carbon nanotube core welded by hybrid carbon shell,has been developed via one-step heating treatment of hybrid molecular brush and further employed as functional interlayer to modify separator of Li-S battery.Owing to the synergistic effect of the highly active CeO_(2−x)nanoparticles and the threedimensional carbon nanonetwork in enhancing the preservation of the soluble polysulfides and boosting the redox kinetics of sulfur species,the NSC-CeO_(2−x)significantly promotes the electrochemical performance of sulfur cathode.As a result,the as-constructed Li-S batteries exhibit an ultrahigh initial sulfur utilization of 92.9%and an extremely large capacity of 751mA h g^(−1) at a high rate of 5 C.Remarkably,a stable capacity of 728 mA h g^(−1)over 300 cycles at 1 C is also achieved.展开更多
水系金属空气电池具有理论能量密度高、安全性高等优点,但受限于金属阳极(如锌、铁、铝、镁)的电化学不可逆性以及碱性电解质对大气中二氧化碳的化学不稳定性.本工作首次设计了一种可充电的铋-空气电池,该电池使用了非碱性的三氟甲磺酸...水系金属空气电池具有理论能量密度高、安全性高等优点,但受限于金属阳极(如锌、铁、铝、镁)的电化学不可逆性以及碱性电解质对大气中二氧化碳的化学不稳定性.本工作首次设计了一种可充电的铋-空气电池,该电池使用了非碱性的三氟甲磺酸铋(Bi(OTf)_(3))水系电解质.得益于三电子反应和相对于标准氢电极+0.32 V的高电位,铋金属负极具有383 mA h g^(−1)的高比容量和1000次循环的良好稳定性,以及99.6%高库仑效率.铋金属负极在Bi(OTf)_(3)电解液中无腐蚀、钝化和析氢等副反应.此外,非碱性的铋-空气电池通过三氧化二铋(Bi_(2)O_(3))的可逆形成/分解,在环境空气中实现了长期运行稳定性(>200 h).这项工作为探索新型水系金属空气电池作为安全稳定的电源系统提供了新思路.展开更多
基金National Natural Science Foundation of China,Grant/Award Numbers:51872336,51925308,52172061National Key Research and Development Program of China,Grant/Award Number:2021YFF0500600+2 种基金Pearl River Talent Plan of Guangdong,Grant/Award Number:2017GC010612Natural Science Foundation of Guangdong,Grant/Award Number:2021A1515011617Science and Technology Program of Guangzhou,Grant/Award Numbers:202102021111,202002020041。
文摘Lithium-sulfur(Li-S)batteries have been regarded as promising next-generation energy-storage devices owing to their inherently high theoretical energy density.Unfortunately,the poor capacity and cycling life caused by severe polysulfide shuttle effect and sluggish redox kinetics in sulfur cathodes greatly impede the practical application of Li-S batteries.Herein,a new class of nanonetworkstructured carbon decorated with oxygen-vacancy-containing cerium oxide nanoparticles(NSC-CeO_(2−x)),in which carbon skeleton is composed of highly conductive carbon nanotube core welded by hybrid carbon shell,has been developed via one-step heating treatment of hybrid molecular brush and further employed as functional interlayer to modify separator of Li-S battery.Owing to the synergistic effect of the highly active CeO_(2−x)nanoparticles and the threedimensional carbon nanonetwork in enhancing the preservation of the soluble polysulfides and boosting the redox kinetics of sulfur species,the NSC-CeO_(2−x)significantly promotes the electrochemical performance of sulfur cathode.As a result,the as-constructed Li-S batteries exhibit an ultrahigh initial sulfur utilization of 92.9%and an extremely large capacity of 751mA h g^(−1) at a high rate of 5 C.Remarkably,a stable capacity of 728 mA h g^(−1)over 300 cycles at 1 C is also achieved.
基金financially supported by the Science and Technology Commission of Shanghai Municipality(STCSM,21511104900 and 20JC1414902)the National Natural Science Foundation of China(52222310).
文摘水系金属空气电池具有理论能量密度高、安全性高等优点,但受限于金属阳极(如锌、铁、铝、镁)的电化学不可逆性以及碱性电解质对大气中二氧化碳的化学不稳定性.本工作首次设计了一种可充电的铋-空气电池,该电池使用了非碱性的三氟甲磺酸铋(Bi(OTf)_(3))水系电解质.得益于三电子反应和相对于标准氢电极+0.32 V的高电位,铋金属负极具有383 mA h g^(−1)的高比容量和1000次循环的良好稳定性,以及99.6%高库仑效率.铋金属负极在Bi(OTf)_(3)电解液中无腐蚀、钝化和析氢等副反应.此外,非碱性的铋-空气电池通过三氧化二铋(Bi_(2)O_(3))的可逆形成/分解,在环境空气中实现了长期运行稳定性(>200 h).这项工作为探索新型水系金属空气电池作为安全稳定的电源系统提供了新思路.