Operando Evaluation of Selectivity and Transference Number of Lithium‐Conductive Membranes

Abstract

What prompted you to investigate this topic?Preventing unwanted movement of species between the positive and negative electrodes is ak ey requirement for next generation lithium batteries, and can be achievedu sing protective membranes, but these are typically evaluated in ex situ conditions which are not representative of battery operation. We wanted to develop am ethodf or quantifying the ability of membranes to block crossover under operando conditions. What is the most significant result of this study?Most significant is that ex situ methods can considerably overestimate the ability of membranes to block crossover, which has important implicationsf or battery performance andl ifetime. The operando method developed in this study provides am ore realistic picture, and is also low-cost and easy to apply, so can be used in future by scientists developing new membranestoevaluate their performance quickly and accurately.What was the biggest surprise?The biggestsurprise was how wellthe simple model presented in the study describest he system,a llowing very easy analysis of the data.Invited for this month'sc over picture is the group of Dr.N uria Garcia-Araez from the University of Southampton (UK). The cover illustrates the key features of an ew method to evaluate membrane selectivity undero perandoc onditions. Read the full text of the

Transference Number Determination in Poor-Dissociated Low Dielectric Constant Lithium and Protonic Electrolytes

“…Therefore, in contrast to the class mentioned above characterized with the limited applicability towards solid polymeric systems the second class of electrochemical methods can be distinguished for concentrated electrolytes. Moving boundary [55][56][57] or Hittorf and Tubandt type experiments (please refer to [58][59][60][61][62] or a view on very specific modifications/applications of this 19th century originating experimental technique), as well as, techniques based on measurements of the EMF performed on the appropriate concentration cells or even quite exotic measurements performed in force fields i.e., in the case when the measured sample is placed radially on a spinning motor. From the general experimental point of view, only the E.M.F.-based experiments revealed their applicability potential towards the solid polymeric systems.…”