Coaxial Electrospun Tai Chi-Inspired Lithium-Ion Battery Separator with High Performance and Fireproofing Capacity

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Organic flame-retardant separators improve battery safety but suffer from poor thermal stability.
• Developing thermally stable and flame-retardant battery separators is crucial for preventing thermal runaway events.

Purpose of the Study:

• To develop a novel core-shell nanofibrous membrane with enhanced thermal stability and flame retardancy for safer lithium batteries.
• To investigate the effect of silicon dioxide (SiO2) and graphene oxide (GO) on the thermal and electrochemical properties of the separator.
• To evaluate the performance of a battery utilizing the composite separator.

Main Methods:

• Coaxial electrospinning was employed to fabricate a core-shell nanofibrous membrane.
• The shell layer comprised polyvinylidene fluoride, SiO2, and GO, while the core contained triphenyl phosphate (TPP).
• Electrochemical performance and thermal stability were assessed using standard battery testing protocols and flame exposure tests.

Main Results:

• The composite separator demonstrated excellent thermal stability and flame retardancy, remaining intact (91.2%) in an open flame for 15 seconds.
• SiO2 and GO incorporation significantly enhanced thermal stability and electrochemical performance.
• Batteries with the composite separator exhibited a high initial capacity (164 mAh/g) and excellent cycling stability (95% capacity retention after 100 cycles).

Conclusions:

• The "internal-cultivating and external-practicing" core-shell strategy effectively improves the safety of organic flame-retardant separators.
• The developed separator provides a promising solution for enhancing the safety of high-performance lithium batteries.
• This approach offers a new pathway for designing advanced battery safety components.