China uses graphene to develop kilowatt aluminum air battery

Comparison of electrochemical performance of graphene-based cathodes and conventional cathodes

In order to meet the evolving needs of smart grids, mobile communications, and electric vehicles, as well as the need for emergency relief, there is an urgent need to develop new chemical power sources with high energy, low cost, small size, and long life. Metal-air batteries (also called metal fuel cells) are chemical power sources that convert the chemical energy of metallic materials directly into electrical energy. Metal air batteries have the advantages of high energy density, low cost, abundant resources, no pollution in green, long life span for discharge, and safety and environmental protection, and have been listed by the state as “National Strategic Emerging Industries Development Plan for the 13th Five-Year Plan”. The National Development and Reform Commission and the Energy Bureau are included in the Action Plan for the Innovation of Energy Technology Innovation (2016-2030). In terms of the backup power supply market for communication base stations, according to incomplete statistics, the number of China's communication base stations in 2016 was nearly 6 million. Traditional communication base stations generally use large-capacity lead-acid batteries and diesel generators as backup power systems. Currently, as many as 10 million sets of lead-acid batteries are used, the volume and mass are relatively large, and they are replaced once every 3 to 4 years. The service life is short. However, metal air batteries have higher specific energy density (up to 400 Wh/Kg or more in the system), long storage time (about 15 years), long standby time (30 to 50 hours), and a wide range of fitting temperatures (20 to 60°C). ) and other advantages, is an excellent alternative to the lead-acid standby power source of the communication base station. In addition, the energy density of metal air batteries is as high as 800Wh/Kg, which is more than four times that of current commercial lithium-ion power batteries. It also has an attractive market prospect in the application of electric vehicle range extenders. However, the development of the metal air battery industry still faces many technical bottlenecks, affecting its application and promotion. There are four reasons for this: First, the catalytic activity of oxygen reduction catalysts currently used in research and development is not high enough, and the power density of the electrodes needs to be improved; second, the air cathode polarization resistance of conventional structures is large and it is difficult to meet high power output; Since the corrosion is serious, the anode utilization rate is not high. Fourth, the problem of thermal runaway of the battery system causes the battery system to be unable to work for a long time.

1000W aluminum air battery power generation system

Since 2013, the Lithium Battery Engineering Laboratory of the Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences has deployed metal-air battery research, and the research team has developed graphene composite catalysts, new structure air cathodes, metal anode alloying, and single cell fabrication processes. A series of advancements have been made, in which graphene composite manganese-based oxide catalysts and new graphene-based high-efficiency air cathodes have increased the power density of single cells by 25% (see Figure 1), significantly improving the overall performance of metal-air batteries.

Adhering to the research philosophy of “Material-to-material, material-to-consumer, and instrument-to-use,” the research team also conducted in-depth research on battery design and system integration technologies, and successfully developed energy density of 400Wh/Kg in 2015. 3KWh, magnesium-air battery power generation system with output power of 300W. Recently, the research team successfully developed a kilowatt aluminum air battery power generation system based on a graphene air cathode (see Figure 2). The energy density of the battery system is as high as 510Wh/Kg, capacity is 20KWh, and output power is 1000W. The actual demonstration shows that the battery system can simultaneously supply power for one television set, one computer, one electric fan, and ten 60W lighting bulbs, which preliminarily validates the power generation and supply capability of the aluminum air battery system. It is reported that the research team is actively designing and developing a 5kW class high-power aluminum air battery system for use in communication base station backup power supplies and electric vehicle range extenders.

The research team has published more than 10 SCI papers and applied for more than 20 patents for inventions on metal air batteries. It has the ability to produce small materials for key materials and components, single cells, and modular battery stacks. It intends to promote the metal air battery industry in the near future. Change.