Bifunctional polymer electrolyte with higher lithium-ion transference number for lithium-sulfur batteries

Lithium-sulfur(Li-S)batteries have attracted enormous interest due to their super-high theoretical energy density(2600 W·h/kg)in recent years.However,issues such as lithium dendrites and the shuttle effect severely hampered the large-scale application of Li-S batteries.Herein,a novel bifunctional gel polymer electrolyte,poly(N,Ndiallyl-N,N-dimethylammonium bis(trifluoromethylsulfonylimide))-P(VDF-HFP)(PDDA-TFSI-P(VDF-HFP),PTP),was prepared by anion exchange reaction to tackle the above problems.Benefited from the interaction between TFSI-and quaternary ammonium ion in PTP,a higher lithium-ion transference number was obtained,which could availably protect Li metal anodes.Meanwhile,due to the adsorption interactions between PDDA-TFSI and polysulfides(LiPSs),the shuttle effect of Li-S batteries could be alleviated effectively.Consequently,the Li symmetric batteries assembled with PTP cycled more than 1000 h and lithium metal anodes were protected effectively.Li-S batteries assembled with this polymer electrolyte show a discharge specific capacity of 813 mA·h/g after 200 cycles and 467 mA·h/g at 3 C,exhibiting excellent cycling stability and C-rates performance.

基于全变分模型的红外焦平面非均匀性校正及其FPGA实现

基于辐射源的定标校正法在工程应用中易受到特殊应用场合以及仪器工作状态偏移等因素影响,输出图像质量欠佳。针对此问题,基于现场可编程门阵列(Field Programmable Gate Array,FPGA)硬件平台实现了全变分模型场景实时校正算法,阐述了模型的应用原理及抑制图像鬼影、退化问题的相关措施。在制冷型长波红外探测器上完成了功能调试及性能测试。实验结果表明,该算法能在20帧图像内完成校正收敛,达到良好的成像校正效果。