Aluminum-air batteries are essentially fuel cells, a type of chemical power source that directly converts the chemical energy of metallic materials into electrical energy.
The development and application of new energy and new materials have consistently driven technological progress, thereby contributing to the advancement of human society. The widespread adoption of electronic products and electric vehicles has led to the development of various types of batteries. Recently, news about aluminum-air batteries has attracted considerable attention.
According to the latest news from the Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, the research team at the institute has developed a kilowatt-level aluminum-air battery power generation system based on a graphene air cathode.
They used graphene-based manganese oxide catalysts and novel graphene-based high-efficiency air cathodes to increase the power density of single cells by 25%, significantly improving the overall performance of metal-air batteries.
The battery system has an energy density of up to 510Wh/kg, a capacity of 20kWh, and an output power of 1000W.
The actual demonstration showed that the battery system can simultaneously power a television, a computer, an electric fan, and ten 60-watt light bulbs, which preliminarily verified the power generation and supply capabilities of the aluminum-air battery system and is a major breakthrough in the field of new energy and new materials.
Aluminum-air batteries are essentially fuel cells, a type of chemical power source that directly converts the chemical energy of metallic materials into electrical energy.
An aluminum-air battery uses aluminum as the negative electrode and oxygen as the positive electrode in a single cell. It consumes only aluminum and a small amount of water during operation. Once the aluminum and water are depleted, it stops working. It is a primary battery and cannot be recharged; the aluminum electrodes must be replaced to continue operation.
Theoretically, the amount of positive electrode active material in this type of battery is infinite, so the theoretical capacity of the battery mainly depends on the amount of negative electrode metal. This type of battery has a larger specific capacity.
As a special type of fuel cell, aluminum-air batteries have enormous commercial potential in applications such as special-purpose, civilian, underwater propulsion systems, backup power sources for telecommunications systems, and portable power supplies.
Advantages and disadvantages of aluminum-air batteries
Advantages of aluminum-air batteries:
It has a high specific energy; the theoretical specific energy of aluminum-air batteries can reach 8100Wh/kg.
Lightweight, an aluminum-air battery with the same energy content weighs only 12% of a lead-acid battery;
It is non-toxic and hazardous, and can be recycled and reused.
Aluminum raw materials are abundant.
The disadvantages of aluminum-air batteries are also obvious:
It is a chemical reaction device that releases electrical energy. It cannot be recharged repeatedly and requires the aluminum electrodes to be replaced to continue working.
Although aluminum-air batteries have high specific energy, they have low specific power.
The charging and discharging speeds are relatively slow, the voltage lags, and the self-discharge rate is relatively high;
A thermal management system is needed to prevent overheating of the aluminum-air battery during operation.
The theoretical specific energy of aluminum-air batteries can reach 8100Wh/kg. In 2014, the actual specific energy of aluminum-air batteries only reached 350Wh/kg, but it is still 7-8 times that of lead-acid batteries, 5.8 times that of nickel-metal hydride batteries, and 2.3 times that of lithium batteries.
After adopting aluminum-air batteries, vehicles can significantly increase their driving range. According to relevant foreign data, in California, USA, there has been a record of electric vehicles using aluminum-air batteries achieving a driving range of 1600km with only one replacement of the aluminum electrode.
The total energy of the traction power type lead-acid battery developed and manufactured in my country is 13.5 kWh, and the total mass is 375 kg.
An aluminum-air battery with the same energy content weighs only 45 kg, which is 12% of the weight of a lead-acid battery.
Because the battery weight is greatly reduced, the vehicle's curb weight is also reduced, which can increase the vehicle's carrying capacity or extend its driving range.
Aluminum is harmless to the human body, can be recycled and reused, and does not pollute the environment. Aluminum is an abundant raw material, and large-scale aluminum smelting plants already exist, resulting in low production costs. Aluminum recycling is convenient and inexpensive. Furthermore, the slow charging speed of aluminum-air batteries can be addressed by replacing the aluminum electrodes.
Although aluminum-air batteries have high specific energy, they have low specific power, slow charging and discharging speeds, voltage lag, and a high self-discharge rate. Therefore, a thermal management system is needed to prevent overheating during operation.
Alcoa Canada and Israel company Phinergy have unveiled a new 100-kilogram aluminum-air battery that stores enough electricity to power a vehicle for 3,000 kilometers.
Cars using this type of battery still need to retain the lithium-ion battery. The aluminum battery only starts operating after the lithium battery is depleted, so it can last a long time, requiring only monthly additions of water. Typically, after about a year, it reaches its lifespan and the aluminum plate needs to be replaced at a service station.
The development of aluminum-air batteries has a history of more than 70 years. In the United States, they are mainly used by the U.S. military and the Special Space Agency. Aluminum-air batteries have been operating on Mars for 13 years and are still functioning normally.
