Schematic illustration of PVDF-HFP and Kevlar polymer structure and their crosslinking.

Major Contributions

1.Development of a Novel Crosslinked PVDF-HFP/Kevlar Nanofiber Separator with Enhanced Mechanical and Electrochemical Properties
A unique composite separator was fabricated by crosslinking PVDF-HFP and Kevlar polymers through intermolecular hydrogen bonding, using electrospinning directly onto copper and MCMB electrode surfaces. This separator exhibits high porosity (65%), excellent electrolyte wettability (contact angle 0°), superior ionic conductivity (1.86 mS cm⁻¹), and a high lithium-ion transference number (0.67). The mechanical strength (16 MPa) and thermal stability (minimal shrinkage at 200°C, decomposition at 564°C) are significantly improved compared to conventional PVDF-HFP and Celgard 2325 separators.

2.Realization of Dual-Function Separator and Artificial Solid-Electrolyte Interphase (ASEI) for Dendrite Suppression and Interfacial Stability
By coating the separator directly onto the electrode surface, an adhesion layer forms that acts both as a separator and as an artificial SEI. This design ensures strong interfacial adhesion, uniform lithium-ion flux, and promotes homogeneous lithium deposition, effectively suppressing dendrite growth and minimizing side reactions. The result is a highly stable lithium plating/stripping performance, with the PVDF-HFP/Kevlar@Cu|Li cell achieving 97% coulombic efficiency after 300 cycles and maintaining performance even at high current densities (5 mA/cm²).

3.Demonstration of Superior Long-Term Cycling and Capacity Retention in Anode-Free and Full Lithium-Ion Cells
The integrated separator approach was validated in both anode-free (Cu||NMC) and full-cell (MCMB||NMC) configurations. The PVDF-HFP/Kevlar@Cu separator enabled stable cycling, high efficiency, and prolonged lifespan, outperforming both freestanding PVDF-HFP/Kevlar and Celgard 2325 separators. In MCMB||NMC full cells, the PVDF-HFP/Kevlar@MCMB separator achieved high coulombic efficiency (~100%) and outstanding capacity retention (82.2% after 400 cycles), compared to 73.8% for freestanding PVDF-HFP/Kevlar and 56.3% for Celgard 2325 after 200 cycles. This demonstrates the practical potential of the separator design for next-generation safe, high-performance lithium batteries.

主要貢獻

1.開發具高機械與電化學性能的全新交聯PVDF-HFP/Kevlar奈米纖維隔離膜
本研究以靜電紡絲法，將PVDF-HFP與Kevlar高分子透過分子間氫鍵交聯，直接製備於銅箔與MCMB電極表面，成功開發出新型複合隔離膜。該隔離膜具備高孔隙率（65%）、極佳電解液潤濕性（接觸角0°）、優異離子導電率（1.86 mS cm⁻¹）及高鋰離子遷移數（0.67）。其機械強度（16 MPa）與熱穩定性（200°C下幾乎無收縮，564°C分解）均大幅優於傳統PVDF-HFP及Celgard 2325隔離膜。

2.實現兼具隔離膜與人工固態電解質界面（ASEI）雙重功能，有效抑制鋰枝晶並提升界面穩定性
隔離膜直接塗佈於電極表面，形成黏著層，兼具隔離膜與人工SEI功能。此設計確保強界面黏著力、均勻鋰離子通量，促進均勻鋰沉積，有效抑制枝晶生成並減少副反應。PVDF-HFP/Kevlar@Cu|Li電池展現高穩定鋰鍍/剝性能，於300循環後庫倫效率達97%，並能於高電流密度（5 mA/cm²）下維持優異表現。

3.於無負極與全電池系統展現長循環壽命與高容量保持率
本研究將整合型隔離膜應用於無負極（Cu||NMC）及全電池（MCMB||NMC）系統，證實其可實現穩定循環、高效率與長壽命，明顯優於傳統PVDF-HFP/Kevlar與Celgard 2325隔離膜。在MCMB||NMC全電池中，PVDF-HFP/Kevlar@MCMB隔離膜於400循環後仍具備高庫倫效率（~100%）與卓越容量保持率（82.2%），遠優於PVDF-HFP/Kevlar（73.8%）與Celgard 2325（56.3%，200循環後）。此成果展現該隔離膜設計於新世代高安全性、高性能鋰電池之實際應用潛力。