Catalytic Polymer Membranes for Improved Oxygen Evolution Reaction in Lithium-Oxygen Batteries

Owing to the decline in our fossil fuels reserves and the growing worldwide demand for energy, sustainable energy storage systems are unquestionably needed. The lithium-oxygen battery, an emerging next generation energy storage system, demonstrates an exceptionally high theoretical energy density which is comparable to the available energy density of gasoline.[1] However, the insufficient round trip efficiency and poor cyclability of current lithium-oxygen batteries must be solved before commercialization for large scale energy storage systems (i.e. smart grid) and electric vehicles. A critical step towards advancing the performance is to develop highly efficient catalytic electrodes for oxygen reduction and oxygen evolution reactions, corresponding to the formation and decomposition of insulating Li₂O₂ products.[2,3] The insulating solid products formed during discharging often deactivate the surface of catalysts on the oxygen electrode, making reversible decomposition of the Li₂O₂products during charging difficult. Therefore, tailored design and effective positioning of catalyst materials in the oxygen electrode are key to avoiding deactivation.[4]

In this presentation, we report the design of a new cell system including catalytic polymer membranes to improve lithium-oxygen battery performance. The catalytic polymer membrane can be inserted between the oxygen electrode and separator, thereby affording more catalytic sites by geometric positioning of catalyst nanoparticles decorated on the polymer membrane. The polymer membrane scaffold can effectively preserve their catalytic activity after the formation of Li₂O₂products on the oxygen electrode (discharging), and consequently faciliate oxygen evolution reaction (charging). Here, we will further discuss the unique effects of the catalytic membrane on the performance and charge/discharge characteristics of the lithium-oxygen battery.

[1] Peter G. Bruce, Stefan A. Freunberger, Laurence J. Hardwick, and Jean-Marie Tarascon, Nature Materials 11 (2012) 19.

[2] Won-Hee Ryu, Taek-Han Yoon, Sung-Ho Song, Seok-Woo Jeon, Yong-Joon Park, and Il-Doo Kim, Nano Letters, 13 (2013) 4190.

[3] Forrest S. Gittleson, Ryan C. Sekol, Gustavo Doubek, Marcelo Linardi and André D. Taylor, Physical Chemistry Chemical Physics, 16 (2014) 3230.

[4] Ryan C. Sekol , Xiaokai Li , Peter Cohen , Gustavo Doubek , Marcelo Carmo, and André D. Taylor, Applied Catalysis B: Environmental, 138 (2013) 285.