Solid-state battery survives 400°F heat, exceeds 1,200 cycles, targets 600-mile range

Next-generation all-solid-state batteries are gaining attention in the electric vehicle battery market, with several battery makers expanding research in the sector. Sunwoda, a Chinese battery manufacturer, has recently announced advances to its polymer-composite approach used for building solid-state batteries.

The company claimed that its latest 20 Ah all-solid-state battery, Xin Bixiao, withstood extreme thermal heat without catching fire or exploding.

Built with a nanoscale high-entropy silicon anode, a single cell of these polymer batteries showed strong thermal performance, passing the hot-box test with temperatures raised to 400 degrees Fahrenheit (200 degrees Celsius).

High-density, long-range

The model has previously achieved an energy density exceeding 400 Wh/kg and a cycle life of more than 1200 cycles at a low external pressure of 1 megapascals (MPa). This it stated is a breakthrough for long-range electric vehicles (EVs), offering a range of over 600 miles (1000 km).

With over 1,200 cycles and capacity retention above 80 percent, the company claimed the battery could support vehicle use for over a decade, assuming annual driving of more than 12,000 miles (20,000 km).

However, the company noted that the thermal and lifespan performance results were not obtained after integrating the entire battery pack in a vehicle. The testing process started earlier this year in May and is still ongoing.

Going forward, the company also plans to build a second-generation sulfide battery by next year at its pre-commercial solid-state battery production line. This manufacturing unit is designed to handle an annual capacity of 0.2 gigawatt-hours (GWh), which is considered small in the battery world, making batteries enough for nearly 2600-2700 electric vehicles per year.

Next stop: Aviation batteries

Beyond the planned automotive batteries of 400Wh/kg capacity, the Chinese battery maker is also eyeing developing aviation battery cells of at least 450Wh/kg. For this project, the company is working with the Guangdong Engineering Research Center. Another segment that the company is aiming to make its mark in is the electric vertical take-off and landing (eVTOL) aircraft batteries. The company is targeting a continuous discharge power density of at least 1,000 W/kg for these aircraft.

However, the company has not yet committed to an official deadline for any of these high-energy-density batteries, nor has it defined the scale of production volumes or commercial orders.

Meanwhile, Contemporary Amperex Technology Co., Limited (CATL), another leading Chinese battery manufacturer, is developing its next-generation solid-state batteries using bisulphide chemistry, a different electrolyte technology. The company announced its 20 Ah solid-state prototype two years ago and has reaffirmed its 2027 target for a small-scale batch production trial.

Earlier this year, Sunwoda unveiled its latest fast-charging EV battery technology that can add about 62 miles (100 km) of range per minute and charge from 10 percent to 97 percent state of charge (SOC) in 9 minutes at room temperature. The claims were made for its new 15C lithium iron phosphate (LFP) battery.

The company said the battery can go from 10 percent to 70 percent in about 5 minutes, then reach 97 percent in another four minutes.

Source: https://interestingengineering.com/energy/sundow-solid-state-ev-batteries-survive-400f