Separator-Integrated, Reversely Connectable Symmetric Lithium-Ion Battery

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Symmetric lithium-ion batteries offer potential advantages in simplified manufacturing and safety.
• Dissolution and shuttle of active materials remain a challenge for symmetric battery performance and longevity.

Purpose of the Study:

• To develop a stable and high-performance separator-integrated, reversely connectable symmetric lithium-ion battery.
• To improve the cycling life and electrochemical performance of symmetric lithium-ion batteries.

Main Methods:

• Synthesized carbon-coated Li3V2(PO4)3 nanoparticles using a solution route and calcination.
• Treated separators with polyvinylidene fluoride to mitigate active material dissolution.
• Developed a separator integration approach for direct electroactive material deposition.

Main Results:

• Achieved a reversible capacity of approximately 87 mA h g(-1) with good cycling stability.
• Demonstrated capacity retention of about 70% after 70 cycles.
• Fabricated a 10-tandem-cell battery with a thickness of 4.8 mm and an output voltage of 20.8 V.

Conclusions:

• Carbon coating and polyvinylidene fluoride treatment significantly enhance the cycling life of symmetric lithium-ion batteries.
• The developed separator integration method is compatible with high electrochemical performance.
• The reversely connectable symmetric battery design enables high voltage output in a compact form factor.