Lithium-ion batteries, of course, are de rigueur in mobile phones, laptop computers, iPods and hybrid automobiles. They are popular due to their high energy density, quick recharge rate and ease of transport — yet the high energy associated with non-aqueous versions comes at a price: They are volatile and prone to explode.
But we recently told you about the development of an aqueous Li-ion battery that uses a salt-water solution as the electrolyte, eliminating volatility without sacrificing safety. Now, that technology has been taken a step further with the development of a Li-ion battery able to maintain its mechanical integrity under adverse conditions — including bending, cutting and liquid submersion.
The new battery is the product of collaborative efforts of researchers from the University of Maryland (UMD), the John Hopkins Applied Physics Laboratory (APL) and the U.S. Army Research Laboratory (ARL).
“UMD and ARL have explored several anode and cathode combinations that can be used within the stability window of our electrolyte,” said Prof. Chunsheng Wang of UMD’s Department of Chemical and Biomolecular Engineering.
“We are starting to transition this technology into novel battery architectures and demonstrate its practical true potential,” added Kostas Gerasopoulos, senior research scientist and principal investigator at APL.
For the new work, the team inserted a salt water electrolyte in polyvinyl alcohol (PVA) solution to create a gel polymer electrolyte (GPE). The GPE was then combined with lithium vanadium fluorophosphates (LiVPO4F) and utilized as both anode and cathode, creating a highly stable and flexible battery.
The battery’s most remarkable attribute, however, is its robustness. “The cell can withstand cutting, and continue to operate in an open cell condition without malfunction,” said Kang Xu, ARL fellow and electrochemistry team leader. “To the best of our knowledge, this feature has not been previously reported for battery chemistries,” the team added in its report.