Alkaline electrolyte solutions are important components in rechargeable batteries and alkaline fuel cells. As the ionic conductivity is thought to be a limiting factor in the performance of these devices, which are often operated at elevated temperatures, its temperature dependence is of significant interest. Here we use NaOH as a prototypical example of alkaline electrolytes, and for this system we have carried out reactive molecular dynamics simulations with an experimentally verified high-dimensional neural network potential derived from density-functional theory calculations. It is found that in concentrated NaOH solutions elevated temperatures enhance both the contributions from proton transfer to the ionic conductivity and deviations from the Nernst-Einstein relation. These findings are expected to be of practical relevance for electrochemical devices based on alkaline electrolyte solutions.Because of their excellent ionic conductivity and high roomtemperature solubility, alkaline electrolyte solutions are widely used in electrochemical devices such as rechargeable batteries and alkaline fuel cells 1,2 . The electrochemically active ion in alkaline electrolytes is the hydroxide ion 3 . OHhas an anomalously high mobility in aqueous solution, as it can diffuse via Grotthuss mechanism which is composed of a series of proton transfer events 4 . Major progress in the understanding of OHsolvation and mobility at low concentration was made by molecular dynamics (MD) simulations based on density functional theory 5-9 and reactive force fields 10-12 , which highlighted the importance of "presolvation", i.e., a thermally induced hydrogen-bond fluctuation, in the diffusion of hydroxide ions 7,10-13 .Although ionic conductivity at low concentrations is welldescribed by the Nernst-Einstein equation, which links the conductivity σ to the self-diffusion coefficients D

Lithium chloride LiCl is widely used as a prototype system to study the strongly dissociated 1-1 electrolyte solution. Here, we combined experimental measurements and classical molecular dynamics simulations to study the ion conduction in this system. Ionic conductivities were reported at both 20 • C and 50 • C from experiments and compared to results from molecular dynamics simulations. The main finding of this work is that transference numbers of Li + and Cl − become comparable at high concentration. This phenomenon is independent of the force fields employed in the simulation and may be resulted from the ion-specific concentration dependence of mobility.