A Highly‐Efficient Composite Separator with Strong Ligand Interaction for High‐Temperature Lithium‐Ion Batteries

• DOI: 10.1002/celc.201800800
• Publication Date: 2018-07-13T16:04:56Z
• Authors: Muhammad Waqas; Chao Tan; Weiqiang Lv; Shamshad Ali; Bismark Boateng; Wenjin Chen; Zhaohuan Wei; Chao Feng; Junaid Ahmed; John B. Goodenough; Weidong He
• Keywords: 7. Clean energy; 01 natural sciences; 0104 chemical sciences

AbstractA PVDF‐HFP/colloidal‐TiO2 composite separator is synthesized for high‐temperature lithium‐ion batteries. Incorporation of colloidal TiO2 in the PVDF‐HFP matrix forms a highly‐uniform composite micro‐structure with strong adsorption interactions between TiO2 and PVDF‐HFP due to the presence of citric acid. The strong interactions are giving rise to advantageous mechanical robustness, separator/electrode interface and electrolyte uptake. The separator shows remarkable stability upon thermal treatment at 150 °C. With a high ionic conductivity up to 1.57×10−3 S cm−1, the LFP/Li cell with PVDF‐HFP/colloidal‐TiO2 composite separator delivers charge‐discharge capacities of 156.95 mAh g−1 (0.1 C) at room temperature and 120.8 mAh g−1 (0.5 C) after annealing cells at 140 °C for 3 hours with a 99 % capacity retention after 100 cycles. The PVDF‐HFP/colloidal‐TiO2 separator demonstrates promising potentials for practical applications in high‐temperature environments.