Scientists have learned how to make batteries from bulletproof vests: they will be better and cheaper than lithium-ion

Scientists from the University of Michigan have made a new discovery in the field of lithium-sulfur batteries that allows them to increase their energy density by a factor of five, according to a press release from the university. The new development is a more powerful and greener alternative to lithium-ion batteries, which rely on cobalt mining and emit large amounts of carbon dioxide during production.

What do scientists know?

The scientific breakthrough is based on the use of an aramid nanofiber mesh obtained from the processing of Kevlar, which is widely used in bulletproof vests. Aramid is needed to stabilize the chemical reaction between the lithium anode and the sulfur cathode in batteries. With the aramid membrane, the researchers were able to inhibit the formation of lithium-sulfur, also known as polysulfide, which would reduce its overall capacity. At the same time, this membrane allowed lithium ions to move from lithium to sulfur and vice versa.

Scientists claim that in addition to increasing the overall capacity, the battery has more than 1000 charge cycles. They estimate that such a battery would have a 10-year lifespan when installed in an electric vehicle.

Project manager Nicholas Kotov says that in the current realities of global electrification of transport, not only charge / discharge cycles are important, but also other requirements: environmental friendliness, low cost of production and simple safe processing. All these requirements are met by a number of scientists from Michigan. The researcher also underlines that such batteries can be made from recycled body armor and other Kevlar products.

Advantages and disadvantages of lithium sulfur batteries

Speaking of the advantages of lithium sulfur batteries in general, it should be noted that they have a high energy density compared to conventional lithium-ion batteries. Lithium sulfur batteries have a theoretical energy density five times higher than its lithium-ion competitor.

Lithium-sulfur batteries are preferred because of their low cost and availability of manufacturing materials. Lithium-sulfur batteries use sulfur, an inexpensive and abundant elemental material, as the cathode, unlike the cobalt and nickel required for lithium-ion batteries. In addition, lithium sulfur batteries have a lower risk of overheating, explosion or fire because they do not use flammable or corrosive electrolyte chemistries.

The environmental friendliness of lithium sulfur batteries is just as important. They can be made from recycled Kevlar products that reduce waste and disposal, such as used body armor as mentioned above. In addition, sulfur is a biodegradable material that reduces environmental pollution.

However, lithium-sulfur batteries still lose to their lithium-ion “brothers” in loss of capacity, which is what Nicholas Kotov tried to avoid in his development. Lithium-sulfur batteries are prone to the formation of polysulfide, which dissolves in the electrolyte and disrupts the contact between anode and cathode. This results in a reduction in battery capacity and efficiency with each charge-discharge cycle.

Until now, lithium sulfur batteries require a longer charge than lithium-ion, which does not satisfy electric vehicle owners.

What awaits the Michigan lithium sulfur battery?

prof. According to Kotov, he has applied for a patent for the aramid membrane and even plans to start a company to promote the new technology. The scientist claims that the battery design is “almost perfect” and has reached the technology’s theoretical limits in terms of capacity and efficiency.

If its technology eventually hits the market, it will join projects like the prototype battery from Michigan-based startup Our Next Energy, which aims to increase the life and capacity of similar batteries for electric vehicles.

Previously Focus He wrote that engineers are developing a new type of floating windmill: why are they so special?