In Situ Polymerization Facilitating Practical High-Safety Quasi-Solid-State Batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Quasi-solid-state batteries (QSSBs) offer improved safety over conventional liquid electrolyte batteries.
• Understanding the mechanisms behind QSSB safety enhancements is crucial for practical applications.

Purpose of the Study:

• To develop practical QSSBs with enhanced safety features.
• To investigate the mechanisms responsible for improved safety in QSSBs.

Main Methods:

• A novel strategy combining an ethylene carbonate-free liquid electrolyte and in situ polymerization was employed.
• Ah-level QSSBs utilizing LiNi0.83Co0.11Mn0.06O2 cathodes and graphite-silicon anodes were fabricated.
• Accelerating rate calorimetry and hot-box tests were conducted to evaluate thermal safety.

Main Results:

• The developed QSSBs demonstrated significantly improved safety, with increased self-heating and onset temperatures (T2) by up to 48.4 °C.
• QSSBs did not undergo thermal runaway (TR) until 180-200 °C, compared to 130 °C for conventional liquid batteries.
• In situ formed polymer skeleton effectively mitigated exothermic reactions, retarded oxygen release, and inhibited crosstalk reactions.

Conclusions:

• The novel QSSB strategy provides a practical solution for high-safety, high-energy-density batteries.
• The findings offer new insights into building safer advanced battery systems.
• The in situ polymer skeleton plays a key role in enhancing thermal stability.