A Rechargeable Li-CO Battery with a Gel Polymer Electrolyte.

The utilization of CO in Li-CO batteries is attracting extensive attention. However, the poor rechargeability and low applied current density have remained the Achilles' heel of this energy device. The gel polymer electrolyte (GPE), which is composed of a polymer matrix filled with tetraglyme-based liquid electrolyte, was used to fabricate a rechargeable Li-CO battery with a carbon nanotube-based gas electrode. The discharge product of Li CO formed in the GPE-based Li-CO battery exhibits a particle-shaped morphology with poor crystallinity, which is different from the contiguous polymer-like and crystalline discharge product in conventional Li-CO battery using a liquid electrolyte. Accordingly, the GPE-based battery shows much improved electrochemical performance. The achieved cycle life (60 cycles) and rate capability (maximum applied current density of 500 mA g ) are much higher than most of previous reports, which points a new way to develop high-performance Li-CO batteries.