Why is fast charging of electric vehicles difficult? Why is 10 minutes of charging time difficult?

As the electric vehicle market expands, the number of electric vehicle consumers is increasing, but voices of dissatisfaction with charging speeds that still take a long time are increasing.

In the early days of electric vehicle launch, charging time was not a big issue due to the interest in electric vehicles. However, as global automakers release numerous electric vehicles, consumers are comparing various electric vehicles and are not as lenient on charging times as they were at first. Therefore, there is a need to introduce a faster and more convenient charging method.

However, there are several difficulties in accelerating the charging speed of electric vehicles. Quickly recharging an electric vehicle battery pack is a much more sensitive process than simply adding fuel to an internal combustion engine. This is because the risks of overheating and chemical reactions in lithium-ion battery cells must be considered in order to maintain a safe level of injected power.

When the battery is connected to a power source, + and – ions spread to the positive electrode. If too many ions are sent at once, they will overheat and remain as deposits of lithium metal. Doing so may reduce battery life or cause the system to explode and cause a fire.

Ultimately, the key to fast charging is to find a way for lithium ions to move freely within the battery without significant damage to energy density.

There are many challenges in providing high-speed charging in a situation where charging infrastructure is currently lacking. Installing a fast charging station would need to be able to supply twice the power of current charging devices of approximately 350 kW. The reality is that it is not easy to install a charging station that can supply such a large amount of power.

Fortunately, researchers, automobile companies, and battery companies in the electric vehicle industry are innovating to shorten charging time to 10 minutes.

Chaoyang Wang, a researcher at Pennsylvania State University, has developed a cell that can be charged to 80% in less than 10 minutes. By using an ultra-thin nickel foil that heats the battery to 60 degrees before charging, it prevents lithium stacking and improves heat dissipation. The developed cells are currently being tested by several automobile manufacturers.

If high-speed charging becomes possible faster than now, it is expected to bring drastic changes to the electric vehicle market. First of all, you will be able to drive long distances without worrying about batteries, and if this happens, sales of electric vehicles may also surge again.

Editor Yeju Ahn yj.ahn@carguy.kr