Rapid charging, new breakthrough technology for lithium batteries

Lithium Batteries are very familiar electronic products and are widely used in mobile phones, notebook computers, and electric vehicles. However, the reputation of lithium batteries also suffers from chronic illnesses such as long charging time and short service life. Recently, the research group of Nanyang Technological University in Singapore invented a new type of fast rechargeable battery that can be charged 70% within 2 minutes and has a service life of up to 20 years, which is 10 times the current battery life.

The Lithium Battery is mainly composed of a positive electrode material (such as lithium cobalt oxide), an electrolyte, and a negative electrode material (such as graphite). When charging, lithium ions are desorbed from the lithium cobalt oxide lattice of the positive electrode material and embedded in the layered graphite after passing through the electrolyte; during discharge, lithium ions are released from the lattice of the layered graphite and embedded in the electrolyte after passing through the electrolyte. Lithium cobalt oxide. During the charge and discharge of the battery, lithium ions transfer back and forth between the positive electrode and the negative electrode, so the lithium battery is also vividly referred to as a "rocking chair battery." In recent years, scientists have shown blowout trends in the development of new lithium batteries, especially high-capacity lithium-sulfur, lithium-oxygen batteries, and nano-silicon batteries. However, due to complex synthesis processes, high costs, and short cycle life, many results have failed. Get popular.

Traditional lithium-ion batteries cannot be quickly charged, but are mainly limited by the safety performance of the graphite electrodes. When the battery is working, a solid electrolyte membrane is formed on the electrode surface, which blocks the “steps” of lithium ions and slows down the lithium ions. Transport speed. The innovation of the newly invented new lithium battery is that it uses an ultra-long titanium dioxide nanotube gel instead of the traditional graphite material as the negative electrode of the battery. This new type of material does not form an electrolyte membrane, and lithium ions can be rapidly embedded to achieve rapid charging. At the same time, thanks to the special structure of one-dimensional titania nanogels, the new battery has achieved a breakthrough in lifespan, with cycle times of up to tens of thousands of times. Assuming one charge a day, it can be used for more than 20 years. Moreover, the titanium dioxide (commonly known as titanium dioxide) raw materials used in this study are low in cost and easy to process, have good battery repeatability, high reliability, and can seamlessly interface with existing processes, and their industrial application prospects are bright.

Lithium batteries appeared in the 70s of the last century. In 1991, Sony Corporation released the first commercial lithium battery, which has since revolutionized the face of consumer electronics. Although lithium batteries are used more and more widely, their endurance and service life have not yet been effectively broken, and they have also restricted the rapid development of electric vehicles and other industries. This new technological breakthrough will bring widespread impact in many fields. In the field of mobile devices, new batteries can avoid the "forced elimination" of some electronic devices; the electric vehicle field will also greatly benefit, not only charging time can be a few Hours are reduced to a few minutes, and users do not need to frequently replace expensive battery packs (approximately US$10,000), which brings benefits to the further popularization of electric vehicles.

However, the current bottleneck for the development of lithium batteries is: If you want to increase the capacity, you must sacrifice the charging speed and cycle life, and it is difficult to maintain a higher capacity by increasing the charging speed. In the future, the upgrading of the battery needs to improve the safety performance on the one hand, such as the research on solid-state semi-solid electrolytes. On the other hand, it is necessary to speed up the research and development of large-capacity cathode materials and achieve a breakthrough in the energy density of lithium batteries. In short, the positive and negative electrodes of the battery as well as the electrolyte material need to develop side by side in concert, so as to be able to make greater progress in terms of form and capacity.

(The author is a professor at Nanyang Technological University, Singapore)