Jin Xiuyu, Zhu Ziting, Miao Qiusu, Fang Chen, Huang Di, Giovine Raynald, Chen Linfeng, Dun Chaochao, Urban Jeffrey J, Fu Yanbao, Li Defu, Liu Katie, Wang Yunfei, Zhu Tianyu, Zhu Chenhui, Tong Wei, Liu Gao
The Energy Storage and Distributed Resources Division (ESDR), Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
Pines Magnetic Resonance Center (PMRC)-Core Facility, College of Chemistry, University of California, Berkeley, CA, 94720, USA.
Adv Sci (Weinh). 2025 May;12(17):e2416995. doi: 10.1002/advs.202416995. Epub 2025 Mar 6.
The eco-friendly processing of conjugated polymer binder for lithium-ion batteries demands improved polymer solubility by introducing functional moieties, while this strategy will concurrently sacrifice polymer conductivity. Employing the polyfluorene-based binder poly(2,7-9,9 (di(oxy-2,5,8-trioxadecane))fluorene) (PFO), soluble in water-ethanol mixtures, a novel approach is presented to solve this trade-off, which features integration of aqueous solution processing with subsequent controlled thermal-induced cleavage of solubilizing side chains, to produce hierarchically ordered structures (HOS). The thermal processing can enhance the intermolecular π-π stacking of polyfluorene backbone for better electrochemical performance. Notably, HOS-PFO demonstrated a substantial 6-7 orders of magnitude enhancement in electronic conductivity, showcasing its potential as a functional binder for lithium-ion batteries. As an illustration, HOS-PFO protected SiOx anodes, utilizing in situ side chain decomposition of PFO surrounding SiOx particles after aqueous processing are fabricated. HOS-PFO contributed to the stable cycling and high-capacity retention of practical SiOx anodes (3.0 mAh cm), without the use of any conducting carbon additives or fluorinated electrolyte additives. It is proposed that this technique represents a universal approach for fabricating electrodes with conjugated polymer binders from aqueous solutions without compromising conductivity.
用于锂离子电池的共轭聚合物粘合剂的环保加工需要通过引入功能基团来提高聚合物的溶解度，而这种策略会同时牺牲聚合物的导电性。采用可溶于水 - 乙醇混合物的基于聚芴的粘合剂聚（2,7 - 9,9 - 二（氧 - 2,5,8 - 三氧杂癸烷）芴）（PFO），提出了一种新方法来解决这种权衡，其特点是将水溶液加工与随后可控的热诱导溶解侧链裂解相结合，以产生分级有序结构（HOS）。热处理可以增强聚芴主链的分子间π - π堆积，以实现更好的电化学性能。值得注意的是，HOS - PFO的电子电导率提高了6 - 7个数量级，展示了其作为锂离子电池功能粘合剂的潜力。例如，制备了HOS - PFO保护的SiOx阳极，利用水性加工后PFO在SiOx颗粒周围的原位侧链分解。HOS - PFO有助于实际SiOx阳极（3.0 mAh cm）的稳定循环和高容量保持，而无需使用任何导电碳添加剂或含氟电解质添加剂。有人提出，该技术代表了一种从水溶液中制备具有共轭聚合物粘合剂的电极的通用方法，且不会损害导电性。
