Review – Safety Aspects of Sodium-Ion Batteries: Prospective Analysis from 1st Generation towards More Advanced Systems

After an introductory reminder of safety concerns pertaining to early rechargeable battery technologies, this review discusses current understandings and challenges of sodium-ion batteries. Sodium-ion technology is now being marketed by industrial promoters who are advocating its workable capacity, use of readily accessible and cheaper key cell components. Often claimed to be safer than lithium-ion cells, currently only limited scientific-sound safety assessment of sodium-ion cells has been performed. However, the predicted sodium-ion development roadmap reveals that significant variants of sodium-ion batteries will potentially enter the market in the near future. With recent experiences of lithium-ion battery failures, sodium-ion battery safety management will constitute a key aspect of successful market penetration. As such this review discusses the safety issues of sodium-ion batteries presenting a twofold innovative perspective: i) in terms of comparison with the parent lithium-ion technology making use of the same working principle and similar flammable non-aqueous solvent basis and ii) anticipating the arrival of innovative sub-chemistries at least partially inspired from successive generations of lithium-ion cells. The authors do hope that the analysis provided will assist the concerned stakeholders in the quest for safe marketing of sodium-ion batteries.