For EVs, Semi-Solid-State Batteries Offer a Step Forward

🌈 Abstract

The article discusses China's investment in the development of solid-state batteries, which are expected to have higher energy density, longer lifespan, and better safety compared to current lithium-ion batteries. It also covers the challenges in commercializing solid-state batteries and the emergence of semi-solid-state batteries as a potential interim solution.

🙋 Q&A

[01] China's Investment in Solid-State Batteries

1. What is China's investment in solid-state battery development?

• China has announced a 6 billion yuan (around $826 million) fund to spur the development of solid-state batteries by the country's leading battery manufacturers.

2. What are the key advantages of solid-state batteries over current lithium-ion batteries?

• Solid-state batteries have 3-4 times higher energy density, offer more charge-discharge cycles, and are less susceptible to thermal runaway reactions that can cause fires.

3. What are the challenges in commercializing solid-state batteries for electric vehicles?

• Existing solid-state battery technologies need to be validated for performance, lifespan, and cost for vehicle propulsion. Researchers also need to determine how the batteries charge, deliver power, and withstand the jarring of driving.

[02] Semi-Solid-State Batteries as an Interim Solution

1. What are the key features of semi-solid-state batteries?

• Semi-solid-state batteries use a gel electrolyte that contains ionic conductors like lithium salts, which supports more efficient ion conductivity and resists the formation of dendrites.
• Semi-solid-state batteries can be produced on conventional lithium-ion battery production lines and are available now, unlike solid-state batteries.

2. How do the performance characteristics of semi-solid-state batteries compare to solid-state and conventional lithium-ion batteries?

• Semi-solid-state batteries have higher energy density (260 Wh/kg) compared to lithium iron phosphate batteries (160 Wh/kg), but lower than the expected energy density of solid-state batteries.
• In tests, semi-solid-state battery packs from Nio and WeLion delivered over 1,000 km of driving range on a single charge.

3. What is the perspective of experts on the future of solid-state and semi-solid-state batteries?

• According to Professor Steve W. Martin, it is incorrect to state that any one battery technology or country's investment will dominate the future, as there are many different solid-state battery technologies being developed.
• Semi-solid-state batteries are seen as a transition between liquid and solid-state batteries, but solid-state batteries are still considered the future.