CO2 Capture Membrane for Long-Cycle Lithium-Air Battery.

Abstract

Lithium-air batteries (LABs) have attracted extensive attention due to their ultra-high energy density. At present, most LABs are operated in pure oxygen (O2) since carbon dioxide (CO2) under ambient air will participate in the battery reaction and generate an irreversible by-product of lithium carbonate (Li2CO3), which will seriously affect the performance of the battery. Here, to solve this problem, we propose to prepare a CO2 capture membrane (CCM) by loading activated carbon encapsulated with lithium hydroxide (LiOH@AC) onto activated carbon fiber felt (ACFF). The effect of the LiOH@AC loading amount on ACFF has been carefully investigated, and CCM has an ultra-high CO2 adsorption performance (137 cm3 g-1) and excellent O2 transmission performance by loading 80 wt% LiOH@AC onto ACFF. The optimized CCM is further applied as a paster on the outside of the LAB. As a result, the specific capacity performance of LAB displays a sharp increase from 27,948 to 36,252 mAh g-1, and the cycle time is extended from 220 h to 310 h operating in a 4% CO2 concentration environment. The concept of carbon capture paster opens a simple and direct way for LABs operating in the atmosphere.