New Flexible Lithium Battery Can Withstand Almost Anything

Lithium-ion batteries have forever changed how we manufacture and use our devices. But we're all too aware of their limitations, especially safety—over the years we've seen countless batteries turn into mini-bombs. That behavior is directly tied to their design, which is why researchers at Johns Hopkins University have built a lithium-ion battery prototype using an aqueous electrolyte that is non-toxic, non-flammable, and flexible enough to bend easily.

You are surrounded by lithium batteries. You may not have thought about it much, but it's true. Your smartphone has one. Your tablet another. The smartwatch, the fitband. Your laptop has several cells. All those discarded phones you keep in a drawer still have their batteries. Vapes, gamepads, earphones, e-readers, wireless keyboards and mice. Tools. We could almost say lithium batteries are like plastic... a central piece of our modern lives.

Unfortunately, they are far from perfect. We appreciate their energy storage capacity, but if they fail catastrophically, the end result always ends in fire. The reason behind that reaction lies in the electrolyte, made up of a combination of flammable lithium salts and various toxic chemicals. If the barrier separating the anode from the cathode breaks down, you end up with a short circuit and heat in a confined space. And when all that heat reaches the electrolyte and the oxygen-rich cathode... fzzzzt!

So what alternative do we have? One option is the so-called aqueous battery, which replaces the traditional electrolyte with a saline solution. The problem is they are too weak for viable commercial use, but a group of researchers at the Applied Physics Laboratory at Johns Hopkins University seems to have hit the mark. Through a series of prototypes, the experts determined that by increasing the concentration of lithium salts in the electrolyte and mixing it with a polymer, they can raise the voltage from 1.2 to 4 volts, a parameter similar to current batteries.

But that's not the end of the story. The battery is non-toxic, non-flammable, can work without a protective casing, and is flexible as a contact lens. Add to that its extraordinary resilience: its creators cut prototypes with scissors, threw them in salt water, simulated ballistic impacts, and even set them on fire—without consequences. In fact, one of the burned parts kept working for a hundred hours.

And the best part is that this isn't a technical curiosity stuck in a lab forever. The team is already in touch with several manufacturers to integrate the new chemistry into today's Li-ion production lines.

The process could be much faster than we imagine, with aqueous batteries reaching the market in less than 24 months. The only thing left is to optimize the electrolyte to increase charge cycles. A good traditional Li-ion cell can handle a thousand cycles, but aqueous batteries handle only about 10 percent of that.

Source: Wired | Official announcement: Click here