How can a lithium battery be safe and strong? This time the researchers used "ice"

Lead: Last year's Note 7 fuel burn accident caused people to worry about lithium batteries, researchers are trying to break the shackles of existing batteries, using "ice" to solve a series of problems such as battery life, safety and bendability.

How can a lithium battery be safe and strong? This time the researchers used "ice"

Mobile devices have encountered bottlenecks in battery life in recent years. Various manufacturers have to solve this problem by increasing battery capacity. However, this solution also has problems. The burning accident of Note 7 has poured a cold water on the whole industry. However, researchers looking for change have not given up, and some people have recently developed a new solution - condensation. It can improve the battery life while ensuring the safety of the lithium battery, and it can be bent to adapt to the future bendable mobile phone.

The solution uses ice-templating to vertically align the structure of the solid electrolyte in the cell, enhancing conductivity. The birth of this new type of battery also paved the way for the concept of flexible smart phones (such as Samsung Galaxy X) and flat panels.

At the moment, the liquid electrolyte used in rechargeable lithium batteries on the market is highly flammable and can easily cause safety problems, and the culprit of the Note 7 burning accident last year was it. Therefore, Columbia University's School of Engineering and Applied Sciences decided to try to replace flammable liquid electrolytes with solid electrolytes.

How can a lithium battery be safe and strong? This time the researchers used "ice"

Traditional liquid electrolytes are extremely flammable

They use ice stencils to give ceramic solid electrolytes a vertically aligned columnar structure, while batteries using ceramic solid electrolytes are significantly safer and more conductive.

Lei Feng.com (public number: Lei Feng) noticed that the battery was also very novel. The researchers first added ceramic particles to the bottom and cooled the aqueous solution. Then the ice layer was grown to extrude a part of the frozen aqueous solution. Let ceramic particles become mainstream in the battery. Finally, create a vacuum environment to sublimate the ice into a vapor state, thus completing the construction of the vertical alignment structure.

Once the vertical alignment structure is fixed, it needs to be combined with a polymer, a macromolecule composed of many repeating subunits, which provides mechanical support for the electrolyte and makes it more flexible.

How can a lithium battery be safe and strong? This time the researchers used "ice"

Vertical alignment structure

“Whether for mobile devices or electric vehicles, flexible solid-state lithium batteries can solve safety problems once and for all, and they can increase the energy density of batteries.” Dr. Yuan Yang said that he is an assistant professor of materials science and engineering at Columbia University. It is also the leader of the team.

In previous experiments, the researchers used a variant of the solution. They used randomly dispersed ceramic particles in the polymer electrolyte, and also tried fiber-like ceramic electrolytes, but these solutions could not achieve vertical alignment.

“At the time, we thought that by simply combining the ceramic electrolyte vertical alignment structure with the polymer electrolyte, lithium ions can be driven into the fast lane and enhance the conductivity of the battery.” Haowei Zhai said that he is the lead author of the research report and Dr. Yuan Yang. s student.

“We believe this is the first time in the industry to use ice stencils to make flexible solid electrolytes. The new electrolytes are not only safe and reliable, but also non-toxic and harmless. The new solution optimizes the conductivity of lithium ions and opens up a new generation of rechargeable batteries. Window," said Haowei Zhai.

After switching to solid electrolysis, the graphite layer used in the original lithium battery anode can be replaced with lithium metal, which can increase the battery energy by 60%-70%.

Next, the team is ready to optimize the quality of the electrolyte bond and try out the new battery.