Multiscale Structural Engineering of Ni‐Doped CoO Nanosheets for Zinc–Air Batteries with High Power Density

• Published in: Advanced materials (Weinheim) Vol. 30; no. 46; pp. e1804653 - n/a
• Main Authors: Li, Yue‐Jiao, Cui, Lan, Da, Peng‐Fei, Qiu, Kang‐Wen, Qin, Wen‐Jing, Hu, Wen‐Bin, Du, Xi‐Wen, Davey, Kenneth, Ling, Tao, Qiao, Shi‐Zhang
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.11.2018
• Subjects: Diffusion; Discharge; Durability; electrocatalysis; Energy storage; Flux density; Metal air batteries; Nanosheets; Nanostructure; Organic light emitting diodes; oxygen reduction reaction; Oxygen reduction reactions; Porosity; Rechargeable batteries; Smartphones; Storage batteries; Structural engineering; transitional metal oxide; Zinc; Zinc-oxygen batteries; zinc–air batteries; oxygen reduction reaction; electrocatalysis; transitional metal oxide; zinc-air batteries; nanosheets
• DOI: 10.1002/adma.201804653
• ISSN: 0935-9648; 1521-4095

Zinc–air batteries offer a possible solution for large‐scale energy storage due to their superhigh theoretical energy density, reliable safety, low cost, and long durability. However, their widespread application is hindered by low power density. Herein, a multiscale structural engineering of Ni‐doped CoO nanosheets (NSs) for zinc–air batteries with superior high power density/energy density and durability is reported for the first time. In micro‐ and nanoscale, robust 2D architecture together with numerous nanopores inside the nanosheets provides an advantageous micro/nanostructured surface for O2 diffusion and a high electrocatalytic active surface area. In atomic scale, Ni doping significantly enhances the intrinsic oxygen reduction reaction activity per active site. As a result of controlled multiscale structure, the primary zinc–air battery with engineered Ni‐doped CoO NSs electrode shows excellent performance with a record‐high discharge peak power density of 377 mW cm−2, and works stable for >400 h at 5 mA cm−2. Rechargeable zinc–air battery based on Ni‐doped CoO NSs affords an unprecedented small charge–discharge voltage of 0.63 V, outperforming state‐of‐the‐art Pt/C catalyst‐based device. Moreover, it is shown that Ni‐doped CoO NSs assembled into all‐solid‐state coin cells can power 17 light‐emitting diodes and charge an iPhone 7 mobile phone. A multiscale structure engineering of Ni‐doped CoO nanosheets from micro‐ through nano‐ to atomic scale for high‐power‐density zinc–air batteries is demonstrated. The engineered zinc–air battery based on Ni‐doped CoO nanosheets realizes sufficient mass transport, abundant catalysts active sites, and excellent intrinsic activity simultaneously, affording a record‐high discharge peak power density of 377 mW cm−2.