This study presents a novel approach for transforming waste polypropylene (PP) disposable masks into high-performance anode materials for lithium-ion batteries (LIBs) through a chemical upcycling process. The disposable masks, typically incinerated or landfilled, are pretreated using sulfonation, nitration, and thermal oxidation to create a thermally stable, crosslinked structure that can withstand high temperature carbonization. The resulting hard carbon materials exhibit a disordered structure, confirmed by X-ray diffraction (XRD) and Raman spectroscopy, with a mixture of graphitic and amorphous phases. These carbon anodes show a maximum discharge capacity of 438.1 mAh g−1, significantly exceeding that of commercial graphite anodes. Furthermore, they demonstrate superior high-rate performance, retaining 56.5 % of their capacity at a 5 C discharge rate, and maintain excellent long-term cycle stability with 97.5 % capacity retention over 100 cycles. The different pretreatment methods produce variations in the morphology and chemical structure of the resulting hard carbon, which influence the electrochemical performance. This work not only offers an effective solution for managing waste masks but also provides a scalable pathway for producing high-value materials for advanced energy storage. The approach highlights the potential of upcycling strategies to convert waste into functional materials for sustainable and high-performance LIBs.

中文翻译：

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将废弃聚丙烯一次性口罩转化为高性能锂离子电池的先进负极材料


本研究提出了一种通过化学升级回收工艺将废弃聚丙烯 （PP） 一次性口罩转化为锂离子电池 （LIB） 的高性能负极材料的新方法。一次性口罩通常被焚烧或填埋，使用磺化、硝化和热氧化进行预处理，以形成可承受高温碳化的热稳定交联结构。所得的硬碳材料表现出无序的结构，X 射线衍射 （XRD） 和拉曼光谱证实了这一点，其中石墨相和非晶相的混合物。这些碳负极的最大放电容量为 438.1 mAh g-1，明显超过商用石墨负极。此外，它们还表现出卓越的高倍率性能，在 5 C 放电速率下保持 56.5% 的容量，并在 100 次循环中保持 97.5% 的容量，保持出色的长期循环稳定性。不同的预处理方法会使所得硬碳的形态和化学结构发生变化，从而影响电化学性能。这项工作不仅为管理废弃口罩提供了有效的解决方案，还为生产用于先进储能的高价值材料提供了可扩展的途径。该方法突出了升级再造策略的潜力，可将废物转化为可持续和高性能锂离子电池的功能性材料。