Key Laboratory of Rubber-plastics, Ministry of Education, School of Polymer Science and Engineering, Qingdao University of Science and Technology, Address: Zhengzhou Rd. 53, Qingdao, CN-266042, China.
Macromol Rapid Commun. 2024 Apr;45(7):e2300645. doi: 10.1002/marc.202300645. Epub 2024 Jan 21.
In this work, hyperbranched polycarbonate-poly(ethylene oxide) (PEO)-based solid polymer electrolytes (HBPC-SEs) are successfully synthesized via a straightforward organo-catalyzed "A"+"B"-ring-opening polymerization approach. The temperature-dependent ionic conductivity of HBPC-SEs, composed of different polycarbonate linkages and various LiTFSI concentrations, is investigated. The results demonstrate that HBPC-SE with an ether-carbonate alternating structure exhibits superior ionic conductivity, attributed to the solubility of Li salts in the polymer matrix and the mobility of the polymer segments. The HBPC1-SE with 30 wt% LiTFSI presents the highest ionic conductivities of 2.15 × 10, 1.78 × 10, and 6.07 × 10 Scm at 30, 60, and 80 °C, respectively. Compared to traditional PEO-based electrolytes, the incorporation of polycarbonate segments significantly enhances the electrochemical stability window (5 V) and Li transference number (0.53) of HBPC-SEs. Furthermore, the LiFePO/HBPC1-SE-3/Li cell exhibits exceptional rate capability and long-cycling performance, maintaining a discharge capacity of 130 mAh g at 0.5C with a capacity retention of 95% after 300 cycles.
在这项工作中，通过简单的有机催化“ A ”+“ B ”-开环聚合方法成功合成了超支化聚碳酸酯-聚（氧化乙烯）（PEO）基固体聚合物电解质（HBPC-SE）。研究了由不同聚碳酸酯键和不同 LiTFSI 浓度组成的 HBPC-SE 的温度依赖性离子电导率。结果表明，具有醚-碳酸酯交替结构的 HBPC-SE 表现出较高的离子电导率，这归因于聚合物基质中盐的溶解度和聚合物链段的迁移率。在 30wt%LiTFSI 下，HBPC1-SE 的离子电导率分别为 2.15×10、1.78×10 和 6.07×10 Scm 在 30、60 和 80°C。与传统的 PEO 基电解质相比，聚碳酸酯段的加入显著提高了 HBPC-SE 的电化学稳定窗口（5V）和 Li 迁移数（0.53）。此外，LiFePO/HBPC1-SE-3/Li 电池表现出出色的倍率性能和长循环性能，在 0.5C 下具有 130 mAh g 的放电容量，经过 300 次循环后容量保持率为 95%。
