High voltage aqueous Li-/Na- ion batteries for electric energy storage application

Liquan Chen

Institute of Physics, Chinese Academy of Sciences


Li- and Na- ion batteries have been considered as the desirable devises for electric energy storage (EES), but their cost, safety hazard, and environmental impact have raised significant concerns in these applications. These concerns were mostly imparted from the non-aqueous electrolytes used therein. Replacing the expensive, inflammable and toxic non-aqueous electrolytes with a water-based counterpart did eliminate those problems. However, the narrow electrochemical stability window (1.23 V) has essentially ruled out most Li/Na ion electrochemical couples which are characterized of high voltage ( > 3.0 V) and high energy outputs. Recently, a new class of Water-in-Salt (WIS) electrolyte was proposed for aqueous lithium ion batteries, which not only achieved successively forming SEI layer in aqueous electrolyte for the first time but also expanded the electrochemical stability window of an aqueous electrolyte to 3.0 V (1). It is expected that this kind of electrolyte will open up a way for us to develop aqueous Li/Na batteries for EES. Subsequently, its derivative systems such as Water-in-Bisalt (WiBS) (2) and WIS based Gel polymer electrolyte (3) has been reported in succession. Meanwhile, benefiting from those achievements, some battery systems are tailor-designed for EES (4, 5), whose are anticipated as one promising and competitive choice in EES market in future. In this talk, we will introduce the main progresses on WIS based aqueous batteries as well as involve some relative fundamental study on ionic transportation and aqueous SEI formation mechanism.


Professor Liquan Chen is an Academician of Chinese Academy of Engineering. He is a professor at the Institute of Physics, Chinese Academy of Sciences. His major research areas are new energy materials and technologies, particularly the solid state ionics. His group has heavily involved in secondary lithium battery research and development of the first Chinese national 863 program and made great achievements, paving the way for the production of lithium ion batteries later on. In recent years, he and his students have obtained some world level achievements on nano-sized alloys as lithium storage materials. Recent years he is studying solid state batteries, Li/S and Li/Air batteries and sodium ion batteries as well as aqueous Li-/Na-ion batteries.