Science and Technology Daily (intern reporter Zhang Jiaxin) Harvard University scientists have developed a new solid-state lithium metal battery for electric vehicles that is expected to be fully charged in three minutes and last for 20 years. The paper was published in the recent issue of Nature.

The startup, Adden Energy, has announced that it has been granted an exclusive technology license by Harvard University's Office of Technology Development to commercialize the technology, which aims to shrink the battery to a palm-sized "soft pack battery" with components encapsulated in an aluminum-coated film.

The battery uses lithium in its pure metal form, rather than the lithium ion used in electric car batteries currently on the market. Also, "solid" means using solid electrodes and a solid electrolyte, rather than the liquid or polymer gel electrolyte found in lithium-ion batteries.

In the lab, the team's battery prototype achieved charging speeds as fast as three minutes and can be cycled more than 10,000 times during its life cycle. Currently, even the best-in-class batteries have only 2,000-3,000 charge cycles, and this technology could be a "game changer," the researchers said.

The new battery's novel and complex design is inspired by the classic British sandwich. Compared with traditional lithium-ion batteries, lithium metal batteries store much more energy in the same volume, while charging time is much less than traditional lithium-ion batteries. But they are prone to forming "dendrites" - a tiny, rigid tree-like structure. The dendrites grow in the cell and their needle-like protrusions are called dendrites. These structures grow like roots into the electrolyte and pierce the barrier that separates the anode from the cathode, potentially causing the cell to catch fire.

A sandwich-like multilayer structure prevents dendritic structures from forming. If you imagine the battery as a sandwich, the first layer is bread (lithium metal anode), then lettuce (graphite coating), followed by a layer of tomatoes (first electrolyte) and a layer of bacon (second electrolyte), and finally another layer of tomatoes and a final piece of bread (cathode). In this design, the dendrites grow in the "lettuce" and "tomato", but stop at the "bacon". The "bacon" barrier prevents dendrites from passing through and shorting out the cell, thus preventing failure.

In addition, the cell is self-healing, meaning its chemistry allows it to backfill the holes created by the dendrites.

The startup says the rapid development of clean energy storage technology is critical to combating climate change. It is estimated that global vehicle electrification alone could reduce global greenhouse gas emissions by 16 percent, and this "new battery model" is seen as key to achieving that goal.

Translated with www.DeepL.com/Translator (free version)