sodium-ion batteries related to sodium clusters” title=”Analysis of thermal runaway mechanisms in sodium-ion versus lithium-ion pouch cells. Comparisons of alkali metal ion behavior in hard carbon and graphite anodes, alongside a study of sodium clusters against LiC6 and their metallic counterparts. Credit: Chinese Academy of Sciences” width=”800″ height=”530″/>
Alarm Bells Ring for Sodium-Ion Batteries: A Closer Look at Safety Risks
A research team from the Qingdao Institute of Bioenergy and Bioprocess Technology within the Chinese Academy of Sciences has uncovered alarming safety issues related to sodium-ion batteries (SIBs), particularly when juxtaposed with lithium-ion batteries (LIBs).
Unexpected Findings on Thermal Runaway
The findings, published in the journal Energy & Environmental Science, indicate that SIBs may be more susceptible to thermal runaway events than previously recognized, challenging their established reputation for safety despite benefits such as cost-efficiency and resource availability.
Sodium-ion batteries have demonstrated impressive advancements over the last ten years, achieving energy densities reaching 160 Wh/kg along with cycle lives surpassing 4,000 charge-discharge cycles. Nevertheless, safety issues remain paramount. This investigation sheds light on how sodium clusters present in hard carbon anodes can instigate premature thermal runaway incidents due to their unexpected electronic behavior.
The Mechanism Behind Increased Reactivity
Prof. Cui Guanglei, who co-authored the study, stated that ”When a battery reaches critical charge thresholds, these sodium clusters can drop the temperature required for self-heating initiation down to as low as 92°C—setting off thermal runaway earlier than what we typically observe with LIBs.” This reactivity is exacerbated by these clusters acting like catalysts that enhance electrolyte breakdown.
Employing solid-state nuclear magnetic resonance (ssNMR) spectroscopy techniques allowed researchers to examine these localized clusters at a quantum level. Their discoveries revealed pronounced metallic properties; notably, these clusters contain more conduction electrons at Fermi energy levels compared to bulk metallic sodium itself—making them exceptionally reactive and escalating risks associated with thermal runaway scenarios.
A Distinct Behavior Compared To Lithium-Ion Batteries
Differentiating from LIBs where exothermic reactions are largely independent of state-of-charge levels (SOC), SIB reactions closely correlate with SOC fluctuations. The formation of disconcerting sodium cluster structures during high SOC phases leads to reduced self-heating onset temperatures well before typical solid-electrolyte interface decomposition occurs in LIB technology. Consequently, even under normal operational conditions, SIBs might face security hazards akin to those linked with overcharging-related sodium plating problems found within traditional battery systems.
Paving The Way Towards Safer Energy Storage Solutions
This research addresses a crucial gap regarding the interplay between cell safety parameters and microenvironments tailored for efficient sodium storage strategies. As part of potential solutions directed towards improving SIB safety profiles dramatically—researchers advocate integrating solid-state electrolytes instead of liquid ones which could mitigate risks related to thermal runaway significantly.
Citation:Sodium-ion batteries reveal serious safety implications due to implications from detection around Na+ ions (February 20th ,2025). Accessed February 21st ,2025 via https://techxplore.com/news/2025-02-sodium-ion-batteries-greater-safety.html p >