Computational screening of doping schemes for LiTi2(PO4)3 as cathode coating materials

In all-solid-state lithium batteries,the impedance at the cathode/electrolyte interface shows close relationship with the cycle performance.Cathode coatings are helpful to reduce the impedance and increase the stability at the interface effectively.LiTi2(PO4)3(LTP),a fast ion conductor with high ionic conductivity approaching 10^-3S·cm^-1,is adopted as the coating materials in this study.The crystal and electronic structures,as well as the Li^+ion migration properties are evaluated for LTP and its doped derivatives based on density functional theory(DFT)and bond valence(BV)method.Substituting part of Ti sites with element Mn,Fe,or Mg in LTP can improve the electronic conductivity of LTP while does not decrease its high ionic conductivity.In this way,the coating materials with both high ionic conductivities and electronic conductivities can be prepared for all-solid-state lithium batteries to improve the ion and electron transport properties at the interface.     

基于拉丝塔光纤光栅的准分布式温盐传感器

提出了一种基于拉丝塔光纤光栅（DTG）的准分布式温盐传感器，可以同时测量海水的温度和盐度。该传感器由多个聚酰亚胺（PI）涂敷DTG和无涂敷DTG串联构成，PI涂敷DTG作为盐度传感组件，盐度的变化会导致聚酰亚胺涂层吸收或释放水而产生膨胀或收缩作用，进而引起光纤光栅中心波长的漂移。温度串扰可以通过使用无涂敷光纤光栅中心波长的变化来补偿。实验结果表明，该传感器能实现温度和盐度的实时测量，对温度和盐度的变化表现出线性响应，且具有良好的重复性。其中，盐度灵敏度平均为-5.58 pm/（mol/L），温度灵敏度平均为10.02 pm/℃。由于拉丝塔光纤光栅的超弱反射特性，该方法可以实现大规模海水温度和盐度的准分布式测量，在海洋工程中有一定的应用前景。