Non‐Aqueous Electrolytes for Sodium‐Ion Batteries: Challenges and Prospects Towards Commercialization

Abstract

Integration of Na‐ion batteries (NIBs) as a complementary energy storage device to the presently dominating Li‐ion battery (LIB) technology is a must, considering the cost and sustainability issues of lithium. However, despite the important laboratory‐scale achievements concerning Na‐ion electrodes and electrolytes, the improvements needed for realizing battery devices to meet users demands are being relatively slow. More specifically, the development of suitable electrolytes remains as the bottleneck that restrains this technology from meeting the commercial requirements, hence defining a future challenge. This review explains the design strategies in use for NIB electrolytes with a special emphasis on intrinsic differences between Li‐ and Na‐ion chemistries, which are at the origin of difficulties associated with the discovery of optimum electrolytes for NIBs. We highlight the key requirements that an electrolyte must satisfy and related experimental techniques that could be used for quick screening of NIB electrolytes in laboratory‐scale for exploiting in commercial NIB devices.

Radiolysis of Electrolytes in Batteries: A Quick and Efficient Screening Process for the Selection of Electrolyte‐Additive Formulations

“…Noteworthily, radiation chemistry can also be used to screen electrolytes in other systems of interest for energy storage, for examples post Li-ion devices such as sodium-ion batteries, [65,66] solid-state batteries [67] as well as supercapacitors. [68,69]…”

Practicality of methyl acetate as a co-solvent for fast charging Na-ion battery electrolytes

“…Considering the Na-ion electrolytes, high Na-ion conductivity is reported due to weaker solvation of the Na + -ion as compared to Li + -ion [23]. However, the interphase formed is often reported to be poorly stable and necessitates the usage of electrolyte additives that can increase the interphase resistance that in turn reduce the power rate capability [24,25]. Hence, to achieve FC Na-ion cells, the electrolyte design needs, besides having high ionic conductivity, to form both highly conductive and stable interphases over a wide temperature range.…”

Deciphering Interfacial Reactions via Optical Sensing to Tune the Interphase Chemistry for Optimized Na‐Ion Electrolyte Formulation

“…However, limited lithium resources together with their uneven distribution in earth necessitate the development of additional complementary battery technologies to fulfil the need [2,3] . Sodium ion batteries (NIBs) that share similar chemistry as well as same production and engineering units with LIBs are expected to fill this gap and prototype NIBs have already been demonstrated by many start-up companies worldwide [4,5] . Still, NIBs lack an optimized electrolyte formulation to realize long cycle life, high safety and low self-discharge which are major requirements for reaching real-life applications [4,6] .…”

“…Sodium ion batteries (NIBs) that share similar chemistry as well as same production and engineering units with LIBs are expected to fill this gap and prototype NIBs have already been demonstrated by many start-up companies worldwide [4,5] . Still, NIBs lack an optimized electrolyte formulation to realize long cycle life, high safety and low self-discharge which are major requirements for reaching real-life applications [4,6] . Back in 20 years, a humongous amount of work has been carried out to reach today's electrolyte formulation for Li-ion batteries.…”

“…[ 4,5 ] Still, NIBs lack an optimized electrolyte formulation to realize long cycle life, high safety, and low self‐discharge which are major requirements for reaching real‐life applications. [ 4,6 ]…”