It’s safer to put diamonds in lithium batteries

Lithium batteries are widely used in mobile devices such as mobile phones and laptops. Dangerous events such as ignition of mobile devices due to battery short circuit are also increasing. Scientists from China and the United States have jointly completed a new study. They have added nano-sized diamond particles to the electrolyte of lithium batteries to prevent the formation of deposits inside the batteries that lead to short circuits and avoid fire accidents caused by battery short circuits.

Lithium battery has high energy density and good discharge performance, and is widely used in industry and consumer electronics. However, if pure metal lithium is used as the electrode, dendritic deposits called “dendrites” are easily formed inside the battery, which will cause short circuit when its size is large to a certain extent. While most lithium batteries use graphite materials with lithium as electrodes, although the occurrence of “dendrites” is reduced to a certain extent, the energy storage effect of lithium batteries is greatly reduced (only one tenth of that of lithium batteries with metal lithium as electrodes).

The researchers added nano-sized diamonds to the electrolyte of lithium battery this time. They found that the deposits generated inside the battery are smooth layers rather than “dendrites”. This new discovery is expected to inhibit the occurrence of “dendrites” when pure lithium metal is used as an electrode, so that lithium batteries can play a better role in safety and efficiency.

It is understood that nano-sized diamonds are extremely tiny diamond particles, with a size less than one tenth of the diameter of hair, and their manufacturing cost is very low. They have a very regular structure and are easy to be naturally arranged into a smooth surface. In the test, the researchers used the lithium battery added with nano diamond to conduct a 200 hour charge discharge cycle test. The test results show that the technology should be sufficient for some industrial applications. Unfortunately, it needs to further verify the performance if it is to be used in smart hands or notebook computers.

At present, this research is published in the new issue of nature communication. The research was jointly completed by Tsinghua University in China and Drexel University in the United States.