Affordable Solid-State Battery with Polymer Electolyte Launches

Key Takeaways

1. Sunwoda is starting large-scale production of solid-state batteries in 2023, aiming to expand capacity by 2026.
2. Their first-generation solid-state battery has an energy density of 400 Wh/kg, nearly double that of current liquid electrolyte batteries.
3. Sunwoda’s semi-solid batteries are seen as a cost-effective alternative, and if their solid-state batteries match these costs, they may attract major car manufacturers.
4. Future prototypes aim for energy densities of 700 Wh/kg, with advancements in polymer electrolyte technology enhancing performance and safety.
5. Ongoing research is pushing the boundaries of solid-state battery technology, with prototypes already exceeding the previously thought limits of 500 Wh/kg.

One of China’s leading battery manufacturers, Sunwoda, is set to begin large-scale production of solid-state batteries this year, with plans to expand capacity by 2026.

First Generation Battery

The company’s initial polymer electrolyte has led to the creation of a solid-state battery ready for production, boasting an energy density of 400 Wh/kg. This figure is nearly twice the average energy density found in current liquid electrolyte batteries used in mass electric vehicles and power stations, such as the new Anker Solix, which is currently 50% off on Amazon. Additionally, Sunwoda has made strides in reducing costs.

While solid-state battery cells can offer higher capacities and enhanced safety due to the absence of volatile liquid electrolytes, manufacturing them in lower volumes remains costly. However, upon revealing its 400 Wh/kg solid-state battery, Sunwoda indicated that it could mass-produce this at prices similar to semi-solid batteries that contain 5% liquid and 95% solid electrolyte.

Bridge Technology

These semi-solid batteries are being utilized by car manufacturers such as NIO, where a 150 kWh pack enables the ET7 sedan to achieve over 650 miles per charge. Moreover, CATL, the largest battery producer globally, regards semi-solid state batteries as a favorable compromise between performance and cost per kWh. If Sunwoda’s all-solid-state battery can match the costs of these semi-solid options, it is likely to attract attention from car makers.

In addition to the solid-state battery with an energy density of 400 Wh/kg, Sunwoda has also developed a prototype boasting 520 Wh/kg, similar to innovations from firms like Toyota, CATL, and Samsung. This prototype features a 3D composite anode that enhances ion transfer, along with a layer filled with tiny bubbles that contains an interface repair agent, which helps maintain the solid electrolyte interphase and minimize dendrite growth that can have harmful effects. Production for this model is anticipated to commence around 2027 when many other solid-state battery manufacturers plan to start their mass production as well.

Future Expectations

By that time, Sunwoda aims to achieve an energy density of 700 Wh/kg across various prototypes, aided by its unique polymer electrolyte technology. The record for solid-state battery energy density was previously held by Chery, China’s largest car exporter, which recently stated it would have vehicles equipped with a 600 Wh/kg solid-state battery available in 2027, utilizing a similar polymer electrolyte method.

The solid-state battery from Sunwoda features a cathode porosity of only 5%, which is five times lower than the usual, yet it enhances ion conductivity by three times. Its “nano-structured high-entropy anode” offers seven times the capacity of conventional graphite anodes and has double the cycle life. The composite polymer electrolyte membrane developed by Sunwoda not only improves ion conductivity but is also elastic and long-lasting. Furthermore, the flexible cell interface coating provides “high ion conduction, robust adhesion, high ductility, and self-healing” properties, according to the company. The resulting 20 Ah cells promise a lifespan of 1,200 cycles and have successfully passed nail penetration and high-temperature safety tests at 200°C.

Continued advancements in this exciting technology are being made in research facilities, with the Chinese Academy of Sciences recently unveiling a flexible solid-state battery prototype featuring a polymer electrolyte that claims to deliver energy density up to 86% greater than current production-ready solid-state options, which range from 350 Wh/kg to 400 Wh/kg depending on the manufacturer.

The 500 Wh/kg solid-state batteries, once believed to be the theoretical limit for today’s technology, are already undergoing testing in prototype vehicles like the Mercedes EQS, capable of covering 750 miles on a single charge. However, their mass production is not expected until 2027, and it will only be in limited quantities for premium electric vehicles.