High Capacity Pouch-Type Li–Air Batteries

The performance of pouch-type Li–air batteries operated in ambient conditions is reported in this work. The batteries use a heat-sealable plastic membrane to function simultaneously as the package material, an diffusion membrane, and a moisture barrier. The large variation in the internal resistance of the batteries related to unstable contacts between electrodes and separators is stabilized by a modified separator that can bind the cell stack together. Cells using the modified separators show improved and repeatable discharge performance. We have also found that 1,2-dimethoxyethane (DME) as a co-solvent in the electrolyte plays an important role in increasing the discharge voltage of these pouch-type cells. However, an overly large amount of DME co-solvent in the electrolyte may lead to decreased capacity due to the eventual loss of DME through the diffusion membrane. Pouch-type Li–air batteries with the modified separator and the optimized electrolyte have demonstrated specific capacities of based on carbon weight and specific energies of based on the complete battery weight, including the package.