Analysis of the development prospects of aluminum air batteries

Aluminum air batteries have recently been sought after by the industry. Someone asked online, "What is the outlook for aluminum air batteries?" The following answers came from battery practitioners.

Jie Su

The rate of air battery is still in the laboratory. From the data point of view, it is indeed a lot of performance improvement. Whether it can save the market, but the result is not equal to the product, the product is not equal to industrialization, and the industrialization is not equal to the user acceptance.

Therefore, the prospect is really bad, it can only be said to be conservative and optimistic.

The preparation process of lithium metal batteries has not been mastered in China, and it may not be possible to make domestic products with mature technology. As far as I know, Israel is better, and there are only a small number of military products.

Zhuo Liang

The news is very good, the battery is also very good, but there is a shortcoming.

That is, it can't be charged!

After the power is discharged, you have to drive the car to a special place to change a battery... What is the difference between this and the refueling?

In fact, in the CitroenC1 mentioned in the news, this aluminum air battery is used with a lithium-ion battery. The daily mileage is generally lithium-ion battery. When it is used up, the aluminum air battery is activated, so this is actually a spare tire. It is only for the case that the daily mileage is used up and the charging station is not found. If you use this too, you have to change it instead of going home to fill it up.

As for Tesla, I have always planned to use lithium-ion batteries as the main force. Recently, I only invested heavily in building Giga factory. In 2020, I only reached the design output. Before that, "we considered the situation of other feasible technologies." That is to say, the most promising is the lithium-ion battery.

Welkincity, lithium ion battery Product Engineer

The aluminum air battery has high purity aluminum Al (containing 99.99% aluminum) as a negative electrode, oxygen as a positive electrode, and an aqueous solution of potassium hydroxide (KOH) or sodium hydroxide (NaOH) as an electrolyte. Aluminum takes up oxygen in the air, produces a chemical reaction when the battery is discharged, and converts aluminum and oxygen into aluminum oxide. The development of aluminum air battery is very rapid, and its application on EV has achieved good results. It is a promising air battery.

Since 100 kilograms can drive 3,000 kilometers, why still need to keep lithium-ion batteries? And do you want to start up after the Li-Ion battery is exhausted?

I think that although the advantages are excellent, the disadvantages are obvious:

1. The specific power is lower and the charging and discharging speed is slower;

2. Voltage lag, self-discharge rate is large;

3. A thermal management system is required to prevent overheating of the aluminum air battery during operation

So the prospects are definitely there, but before these fatal shortcomings are resolved, lithium-ion batteries will not be replaced in a short time.

Various air batteries have long existed, and belong to the reserve battery range. Think about changing a piece of metal when there is no electricity, so perfect. However, such batteries have a common problem: there is no perfect electrolyte membrane solution, so the application of this type of battery has not been able to expand. This membrane should protect the stability of the metal in the lye. It is necessary to transport the current in the form of ions. Consider the role of the electrolyte in the separator in the battery. Think about the role of the electrolyte membrane of lithium metal in lithium thionyl chloride. These are the first breakthroughs in air batteries.

Appendix: Aluminum Air Battery Welcome Machine Tesla Patent Target Metal Air Battery

According to media reports, at the 2014 Atlanta Advanced Automotive Battery Conference, Alcoa and Israel's Phinergy signed a joint development agreement on the further development of the Phinergy aluminum-air battery. Phinergy aluminum-air battery can effectively improve the cruising range of electric vehicles. The specific business scope of the joint development agreement mainly includes new materials, new processes and parts and components. The purpose of this joint development is to promote aluminum-air as soon as possible. The commercialization of batteries analysts said that in addition to the latest research results of Alcoa, Tesla's patented technology is also aimed at metal air batteries, and the future will not rule out the possibility of real commercialization of aluminum air batteries.

Aluminum air battery will become the future battery direction

According to media reports, at the 2014 Atlanta Advanced Automotive Battery Conference (which was held in Atlanta, USA on February 3-7, 2014), Alcoa and Israel's Phinergy further developed the Phinergy aluminum-air battery. The issue signed a joint development agreement.

As a non-rechargeable battery, aluminum air batteries have been around since the 1960s and have very high energy density. The aluminum air battery consists of a catalytic air cathode, an electrolyte and a metal aluminum anode with a theoretical energy ratio of 8.1kWh/kg, which is second only to the lithium-air battery of 13.0kWh/kg. However, since the anodic corrosion of the aluminum air battery during the discharge process generates hydrogen, this not only causes excessive consumption of the anode material, but also increases the electrical loss inside the battery, thereby seriously hindering the commercialization of the aluminum-air battery. In the past, the method for solving the above problems mainly involves doping a high-purity metal aluminum with a specific alloying element to improve the corrosion resistance of the metal aluminum anode, or adding a corrosion inhibitor to the electrolyte.

Dr. Raymond Kilmer, Executive Vice President and Chief Technology Officer of Alcoa, recently stated that Alcoa has extensive expertise in technical materials and has extensive experience in commercializing new products. This will commercialize Phinergy aluminum air batteries. It is also very attractive for Phinergy. At present, the automotive industry is looking for a new zero-emission and non-polluting energy source that can replace traditional gasoline. The Phinergy aluminum air battery can guarantee the car has a good cruising range, so the Phinergy aluminum-air battery is the most likely to replace the traditional gasoline to achieve zero emission of new energy without pollution.

According to Phinergy, a proprietary production process for metal aluminum anodes has been developed that can increase the energy utilization of metal aluminum and reduce unnecessary chemical reaction energy consumption. Phinergy also said it has also developed an advanced battery management system designed to improve battery energy utilization. The air cathode of the Phinergy Aluminium Air Battery is equipped with a dedicated silver-based catalyst that uses a unique and innovative structure that allows oxygen to pass through and blocks carbon dioxide. With this innovative structure, the air cathode of the Phinergy aluminum air battery can effectively avoid the carbonization of the electrode, and the working life can therefore reach thousands of hours. When the Phinergy aluminum air battery is in operation, its internal metal aluminum reacts into aluminum hydroxide. The aluminum hydroxide can be recycled through the processing of the aluminum plant, so that sustainable use can be achieved.

According to Phinergy, the Phinergy aluminum air battery contains 50 aluminum plates, each of which can drive 20 miles of energy alone, so the entire Phinergy aluminum air battery can reach 1000 miles (about 1600 thousand meter). In addition, the Phinergy aluminum air battery has been successfully integrated into the electric vehicle display. In addition to applications in the electric vehicle industry, Phinergy also said that its metal air battery can also be used in fixed energy applications, such as hospitals, commercial emergency generators for data centers, general-purpose generators, and defense applications such as mobile homes and driverless vehicles.

Tesla patented metal air battery

The biggest bottleneck in the development of electric vehicles comes from battery technology, because electric vehicles generally have fatal shortcomings such as long charging time and short driving distance.

But these fatal flaws are being overcome, and a company leaked by a company called Tesla Motors shows that it has made a major breakthrough in the field of automotive batteries. According to media reports, the patent describes the battery pack consisting of a lithium-ion and a metal-air battery that can travel up to 400 miles (650 km). The English letter E stands for economy, Tesla Mode lE is placed on the road to flatten the electric vehicle's large-scale application, it is expected to sell for 30,000 US dollars and the cruising range will reach 200 miles.

In addition, according to foreign media reports, Tesla Motor Corporation filed a patent application for “Electric Vehicle Extended Range Hybrid Battery Pack System” on December 8, 2010, and was approved by the US Patent Office on June 25, 2013. The hybrid power train will not be equipped with a gasoline engine. The hybrid system referred to in this patent is actually from electricity to electricity. Using two types of batteries, it is theoretically possible to give electric vehicles longer cruising range.

According to reports, Tesla's "extended range hybrid battery system" includes standard lithium-ion battery packs, controllers and conventional motors. To complicate matters, there is also a metal air chemistry battery pack. The lithium-ion battery pack supplies power directly to the car, and the metal-air battery pack supplies power to the lithium-ion battery pack. In Tesla's patented design, the metal-air battery pack essentially replaced the extended-range internal combustion engine. The metal air battery has a high energy density and can store more electric energy. In theory, it can function as an extended range, but its power density is relatively low.

According to industry insiders, battery technology needs to make a huge leap to become a true mainstream product. At present, there are still three mountains that have short cruising range, long charging time and high battery cost, which means that electric vehicles cannot be civilianized. The Mode lE that Tesla plans to launch in the future is an electric car product for the general public. Therefore, Tesla needs to compress battery costs to a lower level than it is today.

It is reported that the high energy density battery used by Tesla has a huge disadvantage, that is, the cycle life is low (500 cycles), and one cycle is defined as the complete discharge cycle of the battery rated kWh. The Volt uses 65% of its rated power and uses a life cycle of 0.65 for each full discharge. In other words, Tesla uses a battery rated power of nearly 90%. Take the 85 kWh ModelS as an example. Its single-charge cruising range is 300 kilometers, and each life cycle uses 0.9 life cycles; driving to 100,000 miles. At the time, the battery will discharge 333 times; the depth of discharge (DOD) reaches 90%, which is equivalent to 300 cycles, and can easily reach 500 cycles. The Volanda's single-charge cruising range is only 38 miles. When driving to 100,000 miles, the battery cycle must reach 1710 times, and Bitsla is much higher.

Insiders pointed out that Tesla's "patent" is nothing more than a hybrid battery, similar to the Volanda battery, which can be used for daily driving (usually no more than 40 miles) and needs to be recharged every day. According to driving habits, the extended range battery is rarely used, so it can be a chemical component with a very low cycle life. Moreover, the extended range battery does not necessarily have to be composed of metallic air, and may be any chemical component having high energy density, low cycle life, and low cost. Therefore, Tesla's "extended range hybrid battery system" is just an extension of the concept, whether the concept is desirable, but also need to see the performance of the Tesla ModelE electric car.

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