Directly‐Deposited Ultrathin Solid Polymer Electrolyte for Enhanced CO<sub>2</sub> Electrolysis
Muflih A. Adnan, Ali Shayesteh Zeraati, Shariful Kibria Nabil, Tareq A. Al‐Attas, Karthick Kannimuthu, Cao‐Thang Dinh, Ian D. Gates, Md Golam Kibria
Abstract
Abstract The economic viability of carbon dioxide electroreduction (CO 2 R) relies on improved performance accompanied by scalable system design. Membranes are commonly used for the separation of reduction and oxidation products as well as to provide a suitable micro‐environment for CO 2 R. Commercial membranes often address only one of the key challenges in CO 2 R: either they offer a suitable micro‐environment for CO 2 R (e.g., anion exchange membrane) or suppress carbonate cross‐over (e.g., cation exchange membrane and bipolar membrane). This work presents a cation‐infused ultrathin (≈3 µm) solid polymer electrolyte (CISPE) that concomitantly addresses both challenges via a bidirectional ion transport mechanism and suppressed cathode flooding. This directly‐deposited CISPE (that substitutes the commonly used pre‐made membrane) enables record high full‐cell energy efficiency of 28% at 100 mA cm −2 for one‐step CO 2 electrolysis to ethylene (C 2 H 4 ) with ≈110 h of stable operation. This translates into a record low energy cost of 290 GJ per ton C 2 H 4 for the end‐to‐end process (i.e., CO 2 capture and electroreduction, carbonate regeneration, CO 2 separation from anode and cathode streams) in a membrane electrode assembly CO 2 R. The present work offers a versatile design paradigm for functional polymer electrolytes, opening the door to stable, and efficient electrolysis of high‐value feedstock chemicals and fuels using low‐cost catalysts.