Solid-state batteries
may be the next big thing in
electric vehicle (EV)
technology, but we’re still far from mass production. Significant issues related to their reliability are halting their deployment. Even the best prototypes have proven not to be able to withstand as many charge cycles as the good-old lithium-ion (Li-ion) battery type.
But that hasn’t stopped battery makers and automakers from trying. The day someone arrives on the market with a solid-state battery that can actually last in the long run, the EV industry will leapfrog to a whole new level of immense range and fast charging speeds, potentially rendering the internal combustion engine (ICE) obsolete.
Chinese automaker Xiaomi
, the EV disrupter that shook everyone’s cage with its SU7 sports sedan, also wants a piece of the solid-state pie. It just patented a new prototype that takes the technology one step closer to mass production.
Xiaomi’s Solid-State Patent Aims To Address Challenges Related To Ion Transport Within The Battery
The main issue with solid-state batteries at the moment is how difficult it is to get lithium ions to move through the battery safely, and without damaging the battery itself. So far, while solid-state batteries have proven to be more energy-dense, they haven’t managed to withstand as many charge cycles as lithium-ion batteries. In simpler terms, a solid-state battery is like a Formula 1 car: very fast and effective around a racetrack, but not exactly reliable in the long run. Lithium-ion batteries, on the other hand, are like a trusty daily driver: dependable and reliable, but not all that fast.
There are three main issues surrounding solid-state reliability at the moment: ionic conductivity, interfacial contact issues, and lithium dendrite formation. In English, this essentially means that the batteries are not stable, and eventually just collapse on themselves through short-circuiting.
To mitigate these issues, Xiaomi’s patent uses what the automaker describes as a “layered electrode structure that improves ionic conductivity and energy density”. In other words, the solid electrolyte is stacked in different layers of different active and conductive materials. This also includes conductive agents and binders, while the main electrolyte itself is made of polymers and metal salts.
The general goal of this design is to shorten the transport path of lithium ions within the battery, which leads to fewer risks of premature battery degradation. Finally, Xiaomi says that this new battery would be compatible with its existing lithium-ion manufacturing lines, allowing the automaker to build solid states alongside Li-ion batteries.
Xiaomi’s Solid-State Battery Prototype Promises Over 500 Miles Of Range
If Xiaomi manages to one day mass-produce this prototype, the automaker claims its next-generation EVs will be capable of covering more than 1,200 km (746 miles) of range on a single charge. That’s nuts. But there’s a catch to that number, as it reflects China’s CLTC-rating. In more traditional, North-American EPA terms, this could mean a give-or-take 500-plus range figure, which remains absolutely incredible.
Charging speeds could also skyrocket. The automaker claims its latest battery tech will allow its EVs to recuperate up to 800 km (500 miles) of range in the span of only 10 minutes. Utilizing a cell-to-body (CTB) design, Xiaomi’s super-compact solid-state prototype battery also boasts an impressive 77.8-percent volume efficiency. Measuring only 120 mm in height, including the vehicle’s floor, the battery’s small size aims to improve space optimization in future EVs while positively impacting the vehicle’s overall weight distribution.
While some automakers,
like Toyota
, have claimed that their first solid-state batteries will hit the market sometime in 2027, Xiaomi is a bit less optimistic. The Chinese automaker doesn’t foresee widespread adoption of the technology before 2030. That all being said, solid-state battery research remains highly fascinating, which is why we’ll keep following its progression closely and report everything back here once we know more.