MIT has developed a new electrolyte solution that can prevent large-capacity lithium batteries from cracking
According to foreign media reports, when it comes to replacing battery structures, the design of using high-density lithium metal instead of traditional graphite materials as electrodes is considered very promising. Now, a team from the Massachusetts Institute of Technology (MIT) has developed a new electrolyte solution that can adapt to this chemical reaction and solve one of the key problems hindering the development of the technology to charge electric cars and mobile devices. Longer lifespan paves the way.
The concept of lithium metal batteries raises the prospect of mobile devices and vehicles carrying more charge without adding weight. However, some technical issues still need to be resolved before they become a reality. These include chemical reactions that occur in the electrolyte. Electrolyte is a solution. When lithium ions are charged, it carries lithium ions back and forth between the anode and cathode. More specifically, the atoms in the metal alloy are easily dissolved in the electrolyte solution. As the battery cycles, the electrodes will fall off and will not eventually start to crack and degrade.
Scientists at MIT believe that they have found a viable way forward. It actually emerged from the early research on lithium-air batteries. Although it will take several years, it is another promising possibility. . Some members of the research team have developed a new electrolyte based on organic molecules for lithium-air batteries a few years ago and decided to explore its potential elsewhere.
This involves observing the combination of the electrolyte with the standard cathode used in today's lithium batteries. In the test, the new electrolyte proved to have strong resistance to dissolution of metal atoms, which prevents quality loss and cracking problems that usually occur. It also reduces the accumulation of excess compounds on the electrode surface by more than ten times and still allows the lithium ions needed to charge the battery to move easily. When the electrolyte is combined with the lithium-nickel-manganese-cobalt negative electrode, it has proved to have high performance. In the experiment of the MIT team, the way it interacts with the lithium metal negative electrode may really open some exciting channels. .
MIT’s Yang Shao-Horn said: “This electrolyte has chemical properties that resist oxidation of high-energy nickel-rich materials, which can prevent particle breakage and stabilize the positive electrode during cycling. This electrolyte can also stably and reversibly strip and electroplate lithium. Metal, this is an important step in the realization of rechargeable lithium metal batteries, which have twice the energy of the most advanced lithium-ion batteries. This discovery will promote further electrolyte research and the design of liquid electrolytes for lithium metal batteries, which can be compared with solid electrolytes. Comparable."
The research team said that this new electrolyte can be made into a lithium metal battery, which can store about 420 wH per kilogram, while the current equipment can only achieve 260 hW. This may result in a smartphone or electric car having the same weight, but longer usage time between charges, which may be of great significance to transportation.
The researchers' next goal is to expand the scale of production so that the technology can be affordable for the general public. Although this electrolyte is easy to produce, it involves a seldom-used precursor compound, so it is very expensive to obtain this precursor compound, but this situation may change as production increases. Another advantage of this technology is that it does not require a dramatic redesign of the battery structure, which the team describes as a "temporary" replacement for current electrolytes.
"I think that if we can show the world that this is an excellent electrolyte for consumer electronics, the motivation for further expansion will help drive prices down," said research paper author Jeremiah Johnson.