Water in salt electrolytes are a new type of electrolyte which do not dissociate after 1.2 V unlike regular aqueous electrolytes which dissociate and produce explosive hydrogen gas post 1.2 V of applied voltage.
They are an interesting brand new class of highly concentrated aqueous solutions with wide electrochemically stable windows that make them usable as aqueous battery electrolytes. Although, the high ionic concentration of the salt in the water-in-salt electrolytes implies that these systems are not as well understood as compared to more dilute electrolyte solutions.
There is needed a direct surface force measurement on thin films of water-in-salt electrolytes at several concentrations.
Water in salt electrolytes adopt a layered structure at charged interfaces comprising a structure of a hydrated cation and a nonaqueous anion-rich domain.
Its important to understand capacitance and double-layer behavior of water-in-salt electrolytes with implications for their use in energy storage devices.
Surface Force Balances are used to perform experiments on these electrolytes.
Calcium based Water in salt electrolytes are used. These electrolytes are able to cycle 1000 times at high discharge rates and low discharge rates as well. Calcium Ion batteries can also be made in this manner by using these kind of electrolytes.
References:
https://pubs.acs.org/doi/10.1021/acsami.2c04742
https://pubs.acs.org/doi/10.1021/acs.jpclett.0c03718