Takaki Yuki, Ishizaki Manabu, Nakamura Takashi, Kurihara Masato
Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata, Yamagata 990-8560, Japan.
National Institute of Advanced Industrial Science and Technology (AIST), 4-2-1 Nigatake, Miyagino-ku, Sendai, Miyagi 983-8551, Japan.
ACS Appl Mater Interfaces. 2024 Dec 25;16(51):70531-70543. doi: 10.1021/acsami.4c16113. Epub 2024 Dec 13.
Sustainable energy societies demand rechargeable batteries using ubiquitous-material electrodes of geopolitical-risk-free elements. We aim to develop low-overpotential oxygen-evolution-reaction (OER) catalysts that suppress carbon corrosion of gas-diffusion electrodes (GDEs) to realize two-electrode rechargeable Zn-air batteries (r-ZABs). Herein, single-walled-carbon-nanotube (SWNT) thin films are used as a scaffold for a benchmark OER catalyst, doping-free NiFe-layered double hydroxide (NiFeLDHs), operating in r-ZABs using alkali aqueous electrolytes. Metal compositions of NiFeLDHs are controlled with an atomic-level quality using Prussian-blue-analog nanoparticles of NiFe[Fe(CN)] ( = 0-1). The nanoparticles with dimensions of ∼8 nm adhere to SWNTs on carbon paper as a GDE model by a drop-casting method using their aqueous dispersion solutions. NiFe[Fe(CN)] shows OER activity by hydrolysis for generating NiFeLDH nanodots of metal compositions between NiFe and NiFe with a size distribution of 1.75 ± 0.26 nm and exposing OER-active (018) and (015) planes on SWNTs. The activity is investigated by regulating the loading amounts of the NPs to avoid aggregating the nanodots. An optimal low-loading amount of 270 nmol cm minimizes -corrected overpotential to 156 mV at 10 mA cm. The -uncorrected overpotential is 260 mV and suppresses carbon corrosion of SWNTs and carbon black. Using an r-ZAB half-cell with a Zn foil, OER-driven charging stably proceeds at 10 mA cm over 3 h with an average voltage of 1.99 V vs Zn/Zn. Limited metal electrodes have further improved OER overpotentials by third-element doping, while carbon electrodes still offer room for discovering intrinsically high OER activities of NiFeLDHs without doping.
可持续能源社会需要使用地缘政治风险低的元素制成的无处不在的材料电极的可充电电池。我们旨在开发低过电位析氧反应（OER）催化剂，抑制气体扩散电极（GDE）的碳腐蚀，以实现双电极可充电锌空气电池（r-ZAB）。在此，单壁碳纳米管（SWNT）薄膜用作基准OER催化剂（无掺杂镍铁层状双氢氧化物（NiFeLDHs））的支架，该催化剂在使用碱性水溶液电解质的r-ZAB中运行。使用NiFe[Fe(CN)]（ = 0-1）的普鲁士蓝类似物纳米颗粒，以原子级质量控制NiFeLDHs的金属组成。尺寸约为8 nm的纳米颗粒通过使用其水分散溶液的滴铸法，作为GDE模型附着在碳纸上的SWNTs上。NiFe[Fe(CN)]通过水解表现出OER活性，以生成金属组成介于NiFe和NiFe之间、尺寸分布为1.75±0.26 nm的NiFeLDH纳米点，并在SWNTs上暴露OER活性（018）和（015）平面。通过调节纳米颗粒的负载量来研究活性，以避免纳米点聚集。270 nmol cm的最佳低负载量可将10 mA cm下的校正过电位降至156 mV。未校正过电位为260 mV，可抑制SWNTs和炭黑的碳腐蚀。使用带有锌箔的r-ZAB半电池，在10 mA cm下，OER驱动的充电在3小时内稳定进行，相对于Zn/Zn的平均电压为1.99 V。有限的金属电极通过第三元素掺杂进一步改善了OER过电位，而碳电极仍有空间发现未掺杂的NiFeLDHs固有的高OER活性。
