Lithium-air battery structure enhances efficiency

Lithium-air batteries, which can make the distance between electric vehicles and ordinary cars, have taken a crucial step in terms of practicality. It is well known that the two biggest problems with lithium-air batteries are their low efficiency and their inability to charge and discharge many times. Recently, Yale and MIT researchers discovered a way to alleviate these two problems.

Researchers have developed a nanostructured thin film that reduces the amount of energy required to charge the battery. This, on the one hand, increases the efficiency. At the same time, it is found that the experimental battery can charge up to 60 times without losing storage capacity. This is almost the previous battery. Twice the number of chargeable. (A battery used in an electric car needs about 1,000 charge and discharge cycles.)

The advantages of lithium-air batteries lie in their enormous theoretical energy storage capacity. By weight, it is 10 times more than the traditional lithium battery widely used today. A lithium-air battery allows the car to travel more than 350 miles without the need for gasoline, and is smaller and cheaper than traditional batteries. However, because it is difficult to make the battery capacity close to the theoretical value, some research teams have abandoned the further study of lithium-air batteries. At present, although there is still much work to do before the battery is officially commercialized, the progress of Yale and MIT shows that some key issues are being solved.

Lithium air batteries generate current when lithium ions react with oxygen to produce lithium oxide. The charging process of the lithium-air battery involves the reaction of the reaction - the breakage of the chemical bonds between lithium and oxygen atoms, and the release of oxygen. The problem that has plagued people all the time is that the generated lithium oxide will cover the electrodes of the battery, thereby blocking the contact between the electrode and the catalyst, thereby slowing down the reaction process.

The researchers' solution was to change the structure of the lithium-air battery and add a layer of polymer nanofiber film coated with a catalyst. They stated that lithium oxide does not form on the nanofibers, making the catalyst more efficient.

The experimental battery uses pure oxygen. In order to achieve the theoretical capacity of the lithium-air battery, it is necessary to develop a system that can work in air, which has many challenges. For example, lithium ions tend to react with carbon oxides in the air, and the formation of lithium carbonate makes the charging process of the battery difficult.