Cross-Linked PVA/HNT Composite Separator Enables Stable Lithium-Organic Batteries under Elevated Temperature

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-organic batteries (LOBs) offer advantages in capacity, cost, and sustainability.
• Practical application of LOBs is limited by the shuttling effect and electrode dissolution, especially at high temperatures.

Purpose of the Study:

• To develop a high-temperature separator for LOBs.
• To mitigate the shuttling effect of organic redox intermediates in LOBs.

Main Methods:

• Electrospinning of poly(vinyl alcohol) (PVA) containing halloysite nanotubes (HNTs) to create a cross-linked membrane (EPH-10).
• Incorporation of negatively charged HNTs within the PVA matrix to repel anionic intermediates.
• Testing of the EPH-10 composite membrane as a separator in an anthraquinone (AQ) cathode LOB.

Main Results:

• The PVA/HNT composite separator (EPH-10) effectively suppressed the shuttling of negatively charged organic intermediates.
• The battery demonstrated a high initial discharge capacity of 231.6 mAh g⁻¹ at 25 °C.
• Excellent cycling stability was achieved: 91.4% retention over 300 cycles at 25 °C, and over 89.2% and 80.4% retention after 100 cycles at 60 °C and 80 °C, respectively.

Conclusions:

• The developed EPH-10 composite membrane shows significant potential as a separator for high-temperature LOB applications.
• The cross-linked, negatively charged membrane design addresses key limitations in LOB performance.
• This approach paves the way for more robust and sustainable LOB systems operating under elevated temperatures.