Deng Jiangxiong, Li Qiulin, Xiang Yang, Zeng Yi, Zheng Zhiwen, Nazir Muhammad Altaf, Xu Maowen, Fu Dongxing, Bao Shu-Juan
School of Materials and Energy, Southwest University, Chongqing 400715, PR China; Chongqing Key Lab for Battery Materials and Technologies, Southwest University, Chongqing 400715, PR China.
Chongqing Shuoyingfeng New Energy Technology Co, Chongqing 400026, PR China.
J Colloid Interface Sci. 2026 Jan;701:138707. doi: 10.1016/j.jcis.2025.138707. Epub 2025 Aug 13.
Binders are key components for maintaining the structural integrity of electrodes and improving electrochemical stability of lithium-ion batteries (LIBs). Currently, polyvinylidene fluoride (PVDF) serves as the main binder of LIBs, but suffer a number of drawbacks, including its high fluorine content, the use of organic toxic solvents (N-methylpyrrolidone, NMP) during processing, poor weak adhesion, low mechanical flexibility and non-recyclability. To address the shortcomings of PVDF binder, herein, a fluorine-free, waterborne binder acrylamide (AM) and itaconic (IA) acid grafted carboxylated chitosan (CS) copolymer (CMA), featuring a three-dimensional hydrogen-bonded cross-linking network, is proposed. Its richly branched hydrogen-bonded cross-linking structure increases the contact sites and improves the mechanical properties of the binder, slowing down the volume expansion and stress concentration of the particles, and improving the cycling stability of the battery. Therefore, when CMA is used as a binder for lithium iron phosphate (LFP) cathode, the capacity retention rate is as high as 96.55 % after 400 cycles at 0.5C. Even at higher active materials loading, the battery cycles well. When CMA is used as a binder for silicon (Si) anode, the capacity retention is 85.2 % after 100 cycles at 0.2C, urpassing the performance of PVDF binders tested. Furthermore, CMA exhibits pH-responsive recyclability, enabling efficient electrode component separation via acid treatment and advancing sustainable battery manufacturing, which offers a new perspective for recyclable, eco-friendly lithium-ion battery materials.
粘结剂是维持电极结构完整性和提高锂离子电池（LIBs）电化学稳定性的关键组件。目前，聚偏氟乙烯（PVDF）是LIBs的主要粘结剂，但存在许多缺点，包括其高氟含量、加工过程中使用有机有毒溶剂（N-甲基吡咯烷酮，NMP）、粘结力弱、机械柔韧性差和不可回收性。为了解决PVDF粘结剂的缺点，本文提出了一种无氟的水性粘结剂丙烯酰胺（AM）和衣康酸（IA）接枝的羧甲基壳聚糖（CS）共聚物（CMA），其具有三维氢键交联网络。其丰富的支化氢键交联结构增加了接触位点，提高了粘结剂的机械性能，减缓了颗粒的体积膨胀和应力集中，提高了电池的循环稳定性。因此，当CMA用作磷酸铁锂（LFP）正极的粘结剂时，在0.5C下循环400次后容量保持率高达96.55%。即使在更高的活性材料负载量下，电池也能良好循环。当CMA用作硅（Si）负极的粘结剂时，在0.2C下循环100次后容量保持率为85.2%，超过了测试的PVDF粘结剂的性能。此外，CMA具有pH响应可回收性，能够通过酸处理实现高效的电极组件分离，推动可持续电池制造，这为可回收、环保的锂离子电池材料提供了新的视角。
