Electrochemical oxygen generator with 99.9% oxygen purity and high energy efficiency

Abstract

Under the growing crisis of coronavirus disease 2019 pandemic, the global medical system is facing the predicament of an acute shortage of medical-grade oxygen (O2, ≥ 99.5% purity). Herein, we manufactured an oxygen generation device relying on electrochemical technology. The performance of electrochemical oxygen generator (EOG) was remarkably improved to a practically applicable level, achieving long-term (>200 h), stable, and quick production (>1.5L/min) of high purity O2 (99.9%) under high energy efficiency (496 L/kW·h), viasimultaneous optimizations for intrinsic electrochemical reaction mechanism, electrocatalysts, and external cell structure. The EOG also presents powerful competitiveness in user experience, which finds expression in high portability (4.7 kg), nearly instant O2 production (<1 s), and a quiet working condition (<39 dB). The EOG shows great potential to substitute commercial pressure swing adsorption O2 generation devices, which may significantly impact the traditional oxygen production industry.

New perspective crosslinking electrochemistry and other research fields: beyond electrochemical reactors

“…29,30 To meet the above criteria, it is essential to concurrently focus on optimizations and designs in terms of the catalytic mechanism, catalyst, and reactor structure. In a previous report, 10 Zhang et al designed a coupled ORR and OER electrocatalytic system to construct a high-performance electrochemical O 2 generator (EOG) for in situ medical O 2 production. As illustrated in Fig.…”

“…In the work, Zhang et al conducted a series of designs and optimizations to enhance the performance of the electrochemical O 2 generator (EOG). 10 In alkaline conditions, the ORR and OER can proceed through either a 4-electron transfer (4ET) mechanism adopting OH − ions as intermediates or a 2ET mechanism applying HO 2 − ions as intermediates. The 2ET pathway, by halving the energy requirement per unit of O 2 produced, considerably enhances the O 2 -generation efficiency compared to the 4ET pathway.…”

“…2f), and 496 L kW −1 h −1 energy efficiency. 10 In their study, Zhang et al then examined the practical stability of the stack, conrming its continuous 200 h operation at 1.5 L per min O 2 production without degradation (Fig. 2c), demonstrating excellent prospects for practical application.…”

“…6,7 Further progress includes the design of membrane electrode assembly (MEA) reactors with ion-exchange membranes between the anode and cathode. [8][9][10] This near zero-gap structure minimizes internal polarization resistance, thus considerably boosting the electrochemical reaction efficiency. 11,12 Modern electrochemical reactors have evolved into modular stacks based on MEA structures, maintaining a quite compact size while delivering high power and current density for prolonged, stable, and efficient electrochemical reactions.…”

“…reverse process, electrochemically generating O 2 from water or oxygen-containing ions. 10 By coupling these two electrochemical reactions, O 2 production, removal, or concentration modulation can be achieved. These are pivotal for various applications, such as O 2 production in the medical eld, O 2 removal for food preservation, or manipulating the O 2 concentration to regulate microbial metabolism in microbial fermentation.…”