Electrochemical energy storage (EES) devices and systems play a key role in our modern daily life and social development. The widespread use of portable consumer electronics and rapid market expansion of electric vehicles can be attributed, from a technological perspective to the advances in the rechargeable EES technologies. Especially rechargeable lithium-ion batteries (LIBs) that use an organic liquid electrolyte, graphite-based anode and oxide cathode, have dominated the markets since 1991 owing to their high energy density and long life span. After decades of development, the specific energy density of LIBs increased from about 90 Wh kg–1 to over 250 Wh kg–1, and the cost has decreased from over 1000 US$ kWh–1 to about 250 US$ kWh–1.
However, safety must be taken into account as well as energy density and cost, and it remains a vital issue that impeded the further application of LIBs in large-scale use systems such as electric grids and electric vehicles. Moreover, the safety requirements have been further aggrandized by emerging wearable electronics application, as they are liable to experience greater mechanical damage during daily use. Therefore, developing new EES technologies with better safety is highly required. The typical solution is replacing the flammable organic electrolyte with solid-state or aqueous electrolytes. On the one hand, solid-state batteries using a solid electrolyte have been extensively investigated to provide improved safety as well as higher energy density compared with conventional LIBs. On the other hand, aqueous batteries based on water-electrolyte provide another promising alternative technology for safe rechargeable energy storage due to their low cost, environmental friendliness, and acceptable energy density. This Research Topic aims to summarize recent research progresses and highlight research works on the emerging technologies for safe rechargeable energy storage.
We particularly welcome the submission of Original Research Papers, Short Communications, Mini Reviews and Reviews that related to all fundamental aspects of the emerging technologies for safe rechargeable energy storage, which include but are not limited to:
• All-solid-state batteries
• Li/Na/K ion-based aqueous batteries
• Zn/Mg/Al/Ca ion-based multivalent aqueous batteries
• Polymer electrolyte based rechargeable energy storages
• Nonflammable electrolytes and safe separators for existing Li-ion batteries
Keywords: Safety, Electrochemical energy storage, Solid-state battery, Aqueous battery
Important note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.
