The durability of bamboo based on its chemical and mechanical properties is a crucial consideration for the wood-based industry due to its vulnerability to insects and microorganisms.We investigated the dynamic change...The durability of bamboo based on its chemical and mechanical properties is a crucial consideration for the wood-based industry due to its vulnerability to insects and microorganisms.We investigated the dynamic changes of chemical and mechanical properties of Phyllostachys edulis under air-dry and water storage conditions for 3,6 and 12 months respectively.The chemical properties of P.edulis bamboo culms varied with culm age but insignificantly with culm height.The mechanical properties of P.edulis culms showed an increasing trend with culm age.Water storage condition decreased the ash,SiO2 and lignin content,but increased the ethanol-benzene extracts.It also created an anaerobic environment for bamboo culms in which only anaerobic respiration was possible contributing to reducing the content of soluble sugar and starch,thereby beneficial for decreasing the damage from insects and microorganisms.Moreover,the water storage conditions could maintain culm mechanical performance better.Therefore,the indigenous practice of local people to store bamboo culms in ponds has good science behind it and water storage practices of bamboo culms was recommended.展开更多
LiNi0.85CO0.15-xAlxO2 samples （x=0.025, 0.05 and 0.10） were prepared by solid state reaction at 725℃ for 24 h from LiOH-H2O, Ni2O3, Co2O3 and Al（OH）3 under oxygen flow. Layered LiNiO2 simultaneously doped by Co-A...LiNi0.85CO0.15-xAlxO2 samples （x=0.025, 0.05 and 0.10） were prepared by solid state reaction at 725℃ for 24 h from LiOH-H2O, Ni2O3, Co2O3 and Al（OH）3 under oxygen flow. Layered LiNiO2 simultaneously doped by Co-Al has been tried to improve the cathode performance. The results showed that substitution of optimum amount Al and Co for the Ni in LiNiO2 definitely had some beneficial effect on increasing the capacity and cycling behavior. When increasing x in LiNio.85CO0.15-xAlxO2, the initial discharge capacity decreased and its cyclability increased. Compromising high specific capacity and good cyclability, the optimum x in LiNi0.85Co0.15-xAlxO2 was x=0.05. As a consequence, LiNi0.85Co0.15-xAlxO2 had the first discharge capacity of 186.2 mAh/g and a capacity of 180.1 mAh/g after 10 cycles. Differential capacity vs voltage curves indicated that the co-doped LiNiO2 showed suppression of the phase transitions as compared with LiNiO2.展开更多
复合固体电解质结合了聚合物固体电解质和无机固态电解质的优势,被认为是用于高能量密度全固态锂金属电池最有前景的电解质.但是,电极/电解质界面相容性差以及填料团聚阻碍了复合固态电解质的实用化进程.为解决上述问题,本文利用硅烷偶...复合固体电解质结合了聚合物固体电解质和无机固态电解质的优势,被认为是用于高能量密度全固态锂金属电池最有前景的电解质.但是,电极/电解质界面相容性差以及填料团聚阻碍了复合固态电解质的实用化进程.为解决上述问题,本文利用硅烷偶联剂(KH570)修饰Li_(6.4)La_(3)Zr_(2)Al_(0.2)O_(12)(KH@LLZO),通过原位聚合得到三维分级结构复合固态电解质.电解质中填料(KH@LLZO)含量高(80 wt%)的一侧提供刚性的屏障来抑制锂枝晶的生长;填料含量低(8 wt%)的一侧具有最优的离子电导率,赋予电池体系高效的锂离子传输.得益于电解质独特的分级结构,采用该电解质组装得到的对称锂电池具有0.9 mA cm^(-2)的临界电流密度,并且在0.3 mA h cm^(-2)的面容量下稳定循环超过600 h.组装的Li|LiFePO_(4)电池也展现了长循环稳定性(0.5 C电流密度下循环200圈,容量保持率为91.6%).此外,组装得到的软包电池表现出优异的柔韧性和安全性.本研究提出的采用表面修饰填料(KH@LLZO)构筑得到的分级结构复合固态电解质,为开发无枝晶、高性能全固态锂金属电池开辟了一条新途径.展开更多
基金This work was jointly supported by Yunnan Fundamental Research Project of 2020(202001AT070108)Yunnan Provincial Joint Special Project for Basic Research in Agriculture(No.2017FG001-092)+1 种基金Scientific Research Start-up Fund Project of Southwest Forestry University(No.111817)Yunnan Provincial Department of Education Fund for Scientific Research(No.2020J0413).
文摘The durability of bamboo based on its chemical and mechanical properties is a crucial consideration for the wood-based industry due to its vulnerability to insects and microorganisms.We investigated the dynamic changes of chemical and mechanical properties of Phyllostachys edulis under air-dry and water storage conditions for 3,6 and 12 months respectively.The chemical properties of P.edulis bamboo culms varied with culm age but insignificantly with culm height.The mechanical properties of P.edulis culms showed an increasing trend with culm age.Water storage condition decreased the ash,SiO2 and lignin content,but increased the ethanol-benzene extracts.It also created an anaerobic environment for bamboo culms in which only anaerobic respiration was possible contributing to reducing the content of soluble sugar and starch,thereby beneficial for decreasing the damage from insects and microorganisms.Moreover,the water storage conditions could maintain culm mechanical performance better.Therefore,the indigenous practice of local people to store bamboo culms in ponds has good science behind it and water storage practices of bamboo culms was recommended.
基金This work was supported by the National Natural Science Foundation of China （No. 29833090）.
文摘LiNi0.85CO0.15-xAlxO2 samples （x=0.025, 0.05 and 0.10） were prepared by solid state reaction at 725℃ for 24 h from LiOH-H2O, Ni2O3, Co2O3 and Al（OH）3 under oxygen flow. Layered LiNiO2 simultaneously doped by Co-Al has been tried to improve the cathode performance. The results showed that substitution of optimum amount Al and Co for the Ni in LiNiO2 definitely had some beneficial effect on increasing the capacity and cycling behavior. When increasing x in LiNio.85CO0.15-xAlxO2, the initial discharge capacity decreased and its cyclability increased. Compromising high specific capacity and good cyclability, the optimum x in LiNi0.85Co0.15-xAlxO2 was x=0.05. As a consequence, LiNi0.85Co0.15-xAlxO2 had the first discharge capacity of 186.2 mAh/g and a capacity of 180.1 mAh/g after 10 cycles. Differential capacity vs voltage curves indicated that the co-doped LiNiO2 showed suppression of the phase transitions as compared with LiNiO2.
基金supported by the National Natural Science Foundation of China(51976143)Guangdong Basic and Applied Basic Research Foundation(2020B1515120042)Guangdong Hydrogen Energy Institute of WHUT under Guangdong Key Areas Research and Development Program(2019B090909003)。
文摘复合固体电解质结合了聚合物固体电解质和无机固态电解质的优势,被认为是用于高能量密度全固态锂金属电池最有前景的电解质.但是,电极/电解质界面相容性差以及填料团聚阻碍了复合固态电解质的实用化进程.为解决上述问题,本文利用硅烷偶联剂(KH570)修饰Li_(6.4)La_(3)Zr_(2)Al_(0.2)O_(12)(KH@LLZO),通过原位聚合得到三维分级结构复合固态电解质.电解质中填料(KH@LLZO)含量高(80 wt%)的一侧提供刚性的屏障来抑制锂枝晶的生长;填料含量低(8 wt%)的一侧具有最优的离子电导率,赋予电池体系高效的锂离子传输.得益于电解质独特的分级结构,采用该电解质组装得到的对称锂电池具有0.9 mA cm^(-2)的临界电流密度,并且在0.3 mA h cm^(-2)的面容量下稳定循环超过600 h.组装的Li|LiFePO_(4)电池也展现了长循环稳定性(0.5 C电流密度下循环200圈,容量保持率为91.6%).此外,组装得到的软包电池表现出优异的柔韧性和安全性.本研究提出的采用表面修饰填料(KH@LLZO)构筑得到的分级结构复合固态电解质,为开发无枝晶、高性能全固态锂金属电池开辟了一条新途径.
