- In current electric cars, the anodes of the batteries are made of graphite , a material that leads to deposits on the cathode when charging
- If you instead produce the anode from a mixture of niobate, molybdenum and tungsten , these deposits are avoided and the charging performance increases significantly
- In this way, batteries for electric cars can be produced that enable Extreme Fast Charging , i.e. charging in a maximum of 15 minutes
A new anode material prevents deposits on the cathode and thus significantly increases the charging capacity. The new material can be used to produce lithium batteries that can charge an electric car in just 15 minutes.
Tennessee (United States). The United States Department of Energy (DOE) speaks of Extreme Fast Charging, i.e. the extremely fast charging of an electric car when its battery can be recharged in a maximum of 15 minutes. Electric cars from the upper middle and upper class currently need about 30 minutes to charge their battery from ten to 80 percent.
Scientists at DOE’s Oak Ridge National Laboratory (ORNL) and the University of Tennessee have now discovered a key material that enables such short charge times, according to a publication in the journal Advanced Energy Materials . The anode of the lithium battery consists of a mixture of niobate, molybdenum and tungsten.
Deposits slow down the charging process
Lithium batteries with graphite anodes are used in almost all current electric cars. During the charging process, these decompose the electrolyte solution and cause deposits to form on the cathode. These deposits reduce the stability and charging performance of the battery. As Runming Tao explains, the researchers therefore looked for an alternative material.
“We are looking for new, low-cost materials that can replace and even outperform graphite.”
The main problem here is that most alternative materials bring other problems with them, explains Tao.
“For example, promising niobate oxides require complex syntheses that are difficult to implement on an industrial scale.”
Sol-gel technology in anode production
In addition, the production of niobate oxides and other oxides is very energy intensive and generates toxic waste. However, ORNL scientists found that the sol-gel process can solve this problem. In the sol-gel process, liquid solutions are converted into a gel at low temperatures using a chemical reaction. The researchers were then able to solidify this gel with heat. As Tao explains, this resulted in a durable material that does not form deposits on the anode.
“The material withstands higher voltages than graphite and also does not form deposits on the anode.”
The method is also easily scalable on an industrial scale.
“The exceptional fast charge speed combined with a scalable synthesis make it an attractive candidate for future battery materials.”
Advanced Energy Materials, doi: 10.1002/aenm.202200519