Research Progress towards Understanding the Unique Interfaces between Concentrated Electrolytes and Electrodes for Energy Storage Applications.

by Zheng, Jianming; Lochala, Joshua A.; Kwok, Alexander; Deng, Zhiqun Daniel; Xiao, Jie


The electrolyte is an indispensable component in all electrochem. energy storage and conversion devices with batteries being a prime example. While most research efforts have been pursued on the materials side, the progress for the electrolyte is slow due to the decompn. of salts and solvents at low potentials, not to mention their complicated interactions with the electrode materials. The general properties of bulk electrolytes such as ionic cond., viscosity, and stability all affect the cell performance. However, for a specific electrochem. cell in which the cathode, anode, and electrolyte are optimized, it is the interface between the solid electrode and the liq. electrolyte, generally referred to as the solid electrolyte interphase (SEI), that dictates the rate of ion flow in the system. The commonly used electrolyte is within the range of 1-1.2 m based on the prior optimization experience, leaving the high concn. region insufficiently recognized. Recently, electrolytes with increased concn. (>1.0 m) have received intensive attention due to quite a few interesting discoveries in cells contg. concd. electrolytes. The formation mechanism and the nature of the SEI layers derived from concd. electrolytes could be fundamentally distinct from those of the traditional SEI and thus enable unusual functions that cannot be realized using regular electrolytes. In this article, we provide an overview on the recent progress of high concn. electrolytes in different battery chemistries. The exptl. obsd. phenomena and their underlying fundamental mechanisms are discussed. New insights and perspectives are proposed to inspire more revolutionary solns. to address the interfacial challenges. [on SciFinder(R)]

Advanced Science (Weinheim, Germany)
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