Micro-sized silicon anodes have shown much promise in large-scale industrial production of high-energy lithium batteries.However,large volume change(>300%)of silicon anodes causes severe particle pulverization and ...Micro-sized silicon anodes have shown much promise in large-scale industrial production of high-energy lithium batteries.However,large volume change(>300%)of silicon anodes causes severe particle pulverization and the formation of unstable solid electrolyte interphases during cycling,leading to rapid capacity decay and short cycle life of lithium-ion batteries.When addressing such issues,binder plays key roles in obtaining good structural integrity of silicon anodes.Herein,we report a biopolymer composite binder composed of rigid poly(acrylic acid)(PAA)and flexible silk fibroin(SF)tailored for micro-sized silicon anodes.The PAA/SF binder shows robust gradient binding energy via chemical interactions between carboxyl and amide groups,which can effectively accommodate large volume change of silicon.This PAA/SF binder also shows much stronger adhesion force and improved binding towards high-surface/defective carbon additives,resulting in better electrochemical stability and higher coulombic efficiency,than conventional PAA binder.As such,micro-sized silicon/carbon anodes fabricated with novel PAA/SF binder exhibit much better cyclability(up to 500 cycles at 0.5 C)and enhanced rate capability compared with conventional PAA-based anodes.This work provides new insights into the design of functional binders for high-capacity electrodes suffering from large volume change for the development of nextgeneration lithium batteries.展开更多
风电系统的稳定性对电网安全十分重要,提高风电并网的稳定性依然是当今研究的热点所在。针对永磁直驱风电系统的强耦合以及系统投运后网侧、机侧的波动问题。本文首先分析了永磁直驱风电系统的数学模型和暂态特性;然后在电压环引入一阶...风电系统的稳定性对电网安全十分重要,提高风电并网的稳定性依然是当今研究的热点所在。针对永磁直驱风电系统的强耦合以及系统投运后网侧、机侧的波动问题。本文首先分析了永磁直驱风电系统的数学模型和暂态特性;然后在电压环引入一阶线性自抗扰控制器LADRC(linear active disturbance rejection controller),以其代替传统PI控制器;再通过李雅普诺夫理论分析了采用一阶LADRC时系统的稳定性,得出系统在工程意义上是稳定的。最后,在Matlab/Simulink数字平台进行了仿真测试。多工况下的仿真结果表明,该改进方法与PI控制器相比,具有更优的快速性和抗扰性。展开更多
文摘Micro-sized silicon anodes have shown much promise in large-scale industrial production of high-energy lithium batteries.However,large volume change(>300%)of silicon anodes causes severe particle pulverization and the formation of unstable solid electrolyte interphases during cycling,leading to rapid capacity decay and short cycle life of lithium-ion batteries.When addressing such issues,binder plays key roles in obtaining good structural integrity of silicon anodes.Herein,we report a biopolymer composite binder composed of rigid poly(acrylic acid)(PAA)and flexible silk fibroin(SF)tailored for micro-sized silicon anodes.The PAA/SF binder shows robust gradient binding energy via chemical interactions between carboxyl and amide groups,which can effectively accommodate large volume change of silicon.This PAA/SF binder also shows much stronger adhesion force and improved binding towards high-surface/defective carbon additives,resulting in better electrochemical stability and higher coulombic efficiency,than conventional PAA binder.As such,micro-sized silicon/carbon anodes fabricated with novel PAA/SF binder exhibit much better cyclability(up to 500 cycles at 0.5 C)and enhanced rate capability compared with conventional PAA-based anodes.This work provides new insights into the design of functional binders for high-capacity electrodes suffering from large volume change for the development of nextgeneration lithium batteries.
基金Project(2018YFC0807802)supported by the National Key R&D Program of ChinaProject(41874081)supported by the National Natural Science Foundation of China
文摘风电系统的稳定性对电网安全十分重要,提高风电并网的稳定性依然是当今研究的热点所在。针对永磁直驱风电系统的强耦合以及系统投运后网侧、机侧的波动问题。本文首先分析了永磁直驱风电系统的数学模型和暂态特性;然后在电压环引入一阶线性自抗扰控制器LADRC(linear active disturbance rejection controller),以其代替传统PI控制器;再通过李雅普诺夫理论分析了采用一阶LADRC时系统的稳定性,得出系统在工程意义上是稳定的。最后,在Matlab/Simulink数字平台进行了仿真测试。多工况下的仿真结果表明,该改进方法与PI控制器相比,具有更优的快速性和抗扰性。
