MIT researchers have created a solid-state battery with an innovative design that allows for increased range. Here’s what it looks like
Smartphone owners have something in common with electric car drivers: charging anxiety. All battery-powered devices, from cell phones to Evs, have in fact an autonomy limited to the capacity of the battery that, today, is always in lithium-ion technology. But what about tomorrow? Most likely it will be a solid-state lithium battery.
Solid-state battery technology, in fact, has long been touted as the next revolution in electronics (and electric cars), but today it still has insurmountable technical problems that prevent its adoption in consumer devices. A recent discovery from MIT, however, could change things by bringing solid-state batteries to our devices and allowing a smartphone to stay on for up to three days straight. The innovation consists of a new design of the anode, which is one of the two electrodes through which the electrical current contained in the batteries passes.
The problem with solid-state batteries
Until now, one of the biggest problems with solid-state batteries has been the fact that when the battery is charged, atoms build up inside the lithium metal, causing it to expand. The metal then shrinks again during discharge, when the battery is used. These repeated changes in the size of the metal make it difficult to maintain consistent contact between the materials that make up the battery and tend to cause fractures and detachments. Another problem with solid-state batteries developed to date has been the chemical instability of the electrolytes.
The Solution
The MIT researchers have adopted an innovative design that uses two additional classes of solids, “mixed ion-electronic conductors” (MIECs) and “electronic and lithium-ion insulators” (ELIs), which are chemically stable when in contact with lithium metal. The researchers also developed a three-dimensional honeycomb nanoarchitecture, with additional space left specifically to allow lithium to expand. As the lithium expands in the charging process, it flows into the empty space, moving like a liquid even though it retains a solid crystalline structure.
Three days of charging
The MIT team currently managed to complete 100 full charge/discharge cycles of the new battery, with no sign of fracture. Scientists say that thanks to this new design it will be possible to create much smaller batteries, with the same capacity, that could get to keep a smartphone on for a very long time: up to three days on a single charge.