\u00a9 iStock\/HT Ganzo<\/figcaption><\/figure>\n\u201cNoble-metal-based electrocatalysts demonstrate state-of-the-art electrocatalytic activity and serve as widely accepted benchmarks,\u201d said Li. \u201cBut the high cost, earth scarcity, and poor durability hinder their large-scale practical applications.\u201d<\/p>\n
To boost zinc-air battery performance, therefore, an ongoing search for a high-performance and noble-metal-free option that catalyses both ORR and OER is vital, said Li.<\/p>\n
Combining transition metal atoms for the best results<\/h3>\n
Embedding transition metal atoms into a conductive carbon substrate has been previously shown to produce high electrocatalytic activity due to due to atomic efficiency, unique electronic structure, and diversity in chemical structure. The question then arises as to which metal works best for both ORR and OER.<\/p>\n
The researchers believe that there is not just one option.<\/p>\n
\u201cA single type of active site can hardly promote both ORR and OER kinetics simultaneously to provide outstanding bifunctional electrocatalytic activity,\u201d said Li. \u201cComposing different active sites with respective electrocatalytic activity has been verified as an effective strategy to realise multi-functionality.\u201d<\/p>\n
The team combined two atomic transition metal sites, atomic iron and atomic nickel, and then embedded the composite over a nitrogen-doped carbon (NC) substrate. \u00a0The atomic nickel boosted oxygen evolution whilst the iron successfully achieved high electrocatalytic activity on oxygen reduction. Combined, the transition metal sites realised high-active electrocatalysts in both ORR and OER.<\/p>\n
\u201cThe composite electrocatalyst demonstrated outstanding bifunctional electrocatalytic activity that surpasses the noble-metal-based electrocatalyst and most of the reported bifunctional electrocatalysts based on analogous active sites,\u201d said Li.<\/p>\n
A zinc-air battery, equipped with the FeNi-NC electrocatalyst, was shown to achieve high peak power density, high working rates, and a long lifespan.<\/p>\n
As well as boosting zinc-air battery performance, iron and nickel are cost-effective, scalable alternatives to the more expensive and rarer oxygen electrocatalysts previously used.<\/p>\n
Utilising this strategy for further optimisation<\/h3>\n
Now, the team is developing techniques to optimise the configuration of the atomic metal sites and promote cycling stability under working conditions.<\/p>\n
\u201cThe ultimate goal is to realise high-rate, high-capacity, and long-cycling rechargeable zinc\u2013air batteries for practical applications,\u201d said Li.<\/p>\n","protected":false},"excerpt":{"rendered":"
A team of researchers has designed a strategy to improve zinc-air battery performance with a transition-metal composite. <\/p>\n","protected":false},"author":18,"featured_media":26035,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[24204],"tags":[649,24203],"acf":[],"yoast_head":"\n
Improving zinc-air battery performance with transition-metal composites<\/title>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\t\n\t\n\t\n\n\n\n\n\n\t\n\t\n\t\n