It is imperative that the transition to clean renewable energy occurs within the next few decades because of the depletion of fossil fuels and the increase in air pollution resulting from the climate change caused by human activity.
KAWANISHI, Japan, June 13, 2017 /PRNewswire/ -- Fuji Pigment Co., Ltd. highlights the suppression of the by-product accumulation in rechargeable aluminum-air batteries. Aluminum-air batteries exhibit the following characteristics: a) Their theoretical capacity (8100 Wh/Kg) is 40 times greater than that of lithium-ion batteries (LIBs, 160-200 Wh/Kg). b) Aluminum is an abundant, cheap, and safe material, which can be applied in metal-air batteries. c) All materials (e.g., electrode and electrolyte) are safe and cost-effective; hence, batteries can be easily prepared under normal atmospheric conditions (in contrast to the complex manufacturing of LIBs). Moreover, there are no issues of explosion or flammability as those observed in the manufacture of LIBs.
Although currently commercialized rechargeable LIBs have been widely used in mobile phones, laptops, and electric vehicles, their energy density does not meet the requirements for use in various electric devices for large-scale industrial implementation at an economical cost. A number of researchers have focused efforts on creating next-generation rechargeable batteries, which can surpass the electrochemical properties of LIBs. Among these batteries, metal-air batteries have attracted considerable attention because of their high energy densities. Li, Al, Mg, Na, Zn, Si and Fe have been investigated as metal anode electrodes for metal-air batteries. In particular, Fuji Pigment Co., Ltd., has focused on aluminum as the anode electrode because of its promising high specific capacity and high negative standard electrode potential. In addition, aluminum is one of the abundant metals in the earth's crust; in addition, it is not only the most recycled metal worldwide but also economical.
The theoretical capacities of aluminum-air batteries and commercialized LIBs are 8100 Wh/kg and 160-200 W h/kg, respectively. Hence, aluminum-air batteries exhibit theoretical capacity greater than 40 times as high as that of LIBs.
Nevertheless, aluminum-air batteries have not been actively commercialized because they are basically primary batteries. Recently, a number of studies have examined the possibility of creating rechargeable aluminum-air batteries using ionic-liquid-based electrolytes as the deposition of aluminum is possible on the aluminum anode with such an electrolyte. However, by-products such as Al2O3 and Al(OH)3 have still been observed on the air cathode, which hinder further battery reaction.
In this regard, Dr. Ryohei Mori at Fuji Pigment Co., Ltd. (Hyogo, Japan, http://www.fuji-pigment.co.jp/en/index.html) has invented a new rechargeable aluminum-air battery using ionic-liquid-based electrolytes. In addition, non-oxide ceramic materials such as titanium carbide or titanium nitride have been applied as air cathode materials1.
The use of these air cathode materials led to the suppressed accumulation of by-products at the anode, air cathode, and the entire cell. To the best of our knowledge, this is the first report of such a discovery, and the results can be expected to construct perfect rechargeable aluminum-air batteries.
In addition, Dr. Ryohei Mori has attempted to construct a CR2032-sized aluminum-air battery, which is a standard size for lithium battery coin cells.
Fuji Pigment Co., Ltd. is attempting to commercialize the newly discovered aluminum-air battery. The newly created aluminum-air battery exhibits a cell capacity of least 1200 mAh/g, which is expected to considerably increase with further optimization. As Fuji Pigment Co., Ltd. does not specialize in manufacturing actual battery products for commercialization, they are looking to collaborate with other corporations, research institutes, and universities to create aluminum-air batteries for commercialization. Companies and/or research institutions interested in technical cooperation are invited to contact Fuji Pigment Co., Ltd.
1: Ryohei Mori, Suppression of byproduct accumulation in rechargeable aluminum-air batteries using nonoxide ceramic materials as air cathode materials, Sustainable Energy & Fuels, Advanced Article, 2017, DOI: 10.1039/C7SE00087A