Lithium-ion batteries are one of the most widely used energy storage systems for portable electronics and electric vehicles. Replacing graphite anodes typically used in lithium-ion batteries by lithium metal can further increase the battery’s energy density, because lithium metal has more than ten times the capacity compared to the same weight of graphite. Unfortunately, rechargeable batteries using a lithium metal anode have not yet seen largescale commercialization. A key reason is that, each time such a battery undergoes a charge-discharge cycle, dendrites—branching tree-like crystalline structures—grow inside. These dendrites can shorten battery life and even cause short circuits that may lead to fires or explosions. Removing the lithium anode from rechargeable batteries could solve this problem, increase energy density, and lower production costs. 

Researchers at Pacific Northwest National Laboratory have developed an anode-free rechargeable lithium battery with significantly increased energy density and ease of assembly. Current lithium-ion batteries include multiple stacks of anodes, anode current collectors, separators, and cathodes soaked in an electrolyte. When assembled, PNNL’s anode-free rechargeable battery comprises an anode current collector and a cathode with a separator in between, as well as an electrolyte consisting of a salt or salt mixture dissolved in a solvent, solvent mixture, and/or polymer. The salt or salt mixture can be made up of various types of lithium salts. The minimal number of components means PNNL’s battery is less expensive to produce then current batteries. The lack of an anode increases the energy density of the battery and eliminates dendrite growth, resulting in longer battery life and less chance of safety hazards. 

APPLICABILITY

The anode-free rechargeable battery could be used to power electronic devices, electric vehicles, and even the electric grid.