Solid-state batteries (SSBs) exhibit distinct performance characteristics in extreme temperatures, with challenges particularly pronounced at low and high temperature extremes.
Performance in Low Temperatures
- At lower temperatures, such as near or below room temperature (around 25-30 °C) down to sub-zero conditions, solid-state batteries tend to suffer from sharply increased internal resistance due to reduced ionic conductivity of solid electrolytes. Lithium ions have difficulty moving through the solid electrolyte at these cooler temperatures, causing significant drops in power delivery and available energy.
- Ionic conductivity can decrease by up to two orders of magnitude between 25 °C and -20 °C, which impairs not only discharging capacity but also charging performance. This limitation makes SSBs particularly sensitive to cold weather, impacting their usability especially in electric vehicles exposed to ambient temperature variations.
- New research and technologies, including thermally-optimized cell architectures, novel polymer electrolyte membranes, and selective heating mechanisms, aim to mitigate this temperature sensitivity to extend operational range and improve performance in cold environments.
Performance in High Temperatures
- Solid-state batteries generally operate better at elevated temperatures because ionic conductivity in solid electrolytes improves significantly with heat. For example, some alternative solid electrolytes perform well at around 60 °C or higher, allowing smooth lithium-ion transport even at high power rates (~1C). Some applications like electric buses use SSBs operating at ~80 °C to maintain performance.
- However, high temperatures also introduce challenges: solid electrolytes and other battery components are susceptible to thermal degradation. Chemical reactions, including decomposition of the solid electrolyte and reactions at electrode-electrolyte interfaces, accelerate at elevated temperatures causing capacity fade and increasing internal resistance over time.
- Mechanical stresses arise from thermal expansion mismatches between battery components (electrodes, current collectors, solid electrolyte), potentially causing delamination, loss of electrical contact, and structural failure.
- Electrochemical instability at high voltages and temperatures can lead to electrolyte breakdown and short circuits, restricting the upper operational temperature and voltage limits of SSBs.
Summary Table
| Temperature Range | Effects on Solid-State Batteries | Mitigations/Design Focus |
|---|---|---|
| Low (below ~25 °C) | Increased resistance and reduced ionic conductivity; severe drop in power and capacity | Thermally optimized cells, selective heating, novel polymer electrolytes |
| High (above ~60 °C) | Improved ionic conductivity but risk of thermal degradation, mechanical stress, and electrochemical instability | Material selection, interface engineering, thermal management, robust cell design |
In conclusion, solid-state batteries perform well in high temperature conditions when adequately managed but face performance degradation at lower temperatures due to increased resistance. Ongoing research focuses heavily on overcoming these temperature limitations to unlock their full potential, especially for applications like electric vehicles that encounter wide ambient temperature ranges.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-do-solid-state-batteries-perform-in-extreme-temperatures/
