Insight 05: Solid-State Batteries – The Technology of the 2030s but the Research Challenge of the 2020s
Summary
The development of solid-state batteries that can be manufactured at a large scale is one of the most important challenges in the battery industry today. The ambition is to develop solid-state batteries, suitable for use in electric vehicles, which substantially surpass the performance, safety, and processing limitations of lithium-ion batteries. In contrast to research into lithium-ion batteries, which will provide incremental gains in performance toward theoretical limits, research into solid-state batteries is long-term and high-risk but also has the potential to be high-reward.
Focus of the Insight
The Insight outlines main advantages of SSBs, their commercial applications, technology disruption story, research challenges and the Faraday Institution’s SSB Research Project (SOLBAT).
Conclusion
There are currently two major types of SSEs that may rival liquid electrolytes: inorganic solids and organic polymers. The inorganic solids considered most likely to succeed can be further divided into sulfide and oxide materials. In order to compete with liquid electrolytes, SSEs need to possess exceptional fast charging performance (i.e. high lithium ionic conductivity), safe operation, and easy processability. Each of these types of solid electrolyte appears to have excellent performance in some areas, but poor performance in other. One research challenge of the next decade will be to discover and deploy SSE materials combining acceptable properties in all three areas.
SSB research efforts over the past few decades worldwide have delivered mixed results. Micro-batteries and the
elevated-temperature polymer battery can perhaps be described as notable breakthroughs. Ceramic solids, including garnet oxides and several sulfides, are sufficiently conductive that electrolytes are also no longer the biggest hurdle facing SSB development. The key barriers are preventing unwanted side reactions at the interface between the electrolyte and both electrodes and in improving the mechanics throughout the cell.
It will also be a major challenge to manufacture SSBs commercially as SSEs are complex materials to process. At present, only very small, low-power SSBs are economically viable such as those incorporated in heart pacemakers. This is because as they become larger and more powerful, the problems related to performance, safety and processing, as well as financial cost, are amplified. So far, no one has been successful in solving these problems at scale.