Generally, economical recycling processes based on physical methods for recycling of photovoltaic (PV) modules include crushing or milling steps, accompanied by impurity contamination during the silicon (Si) recovery process of PV modules. Previous studies have deal with the contamination of metals, which can be treated relatively easily during further etching steps. However, the contamination of titanium dioxide (TiO) from the backsheet during the separation of modules has not been considered. In particular, subsequent chemical treatments is hard to remove the TiO nanoparticles. This study presents a 2-step milling process including dry and wet sequences to control both the contamination and size of recovered Si (ReSi) powders directly recycled from PV modules. The proposed method achieved a tenfold reduction in TiO concentration in ReSi, attained through the different sedimentation rates exhibited by Si and TiO particles in the solvent during wet process. Moreover, the current methodology seamlessly establishes dry and wet milling conditions for minimizing the size of the ReSi powder by optimizing the ratio of milling media and milling time. The ReSi powders, of various particle sizes, were evaluated as anode materials for lithium-ion battery. In addition, the cycling performance and volume change of micro- and nano-sized ReSi were compared to validate the effect of 2-step milling. Nano-sized ReSi exhibited a 35.33% improvement in lithium-ion battery retention compared to micro-sized ReSi, along with a 57.67% decrease in volume expansion rate.

中文翻译：

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从光伏组件回收中获取可持续锂离子电池阳极的实用两步研磨工艺

一般来说，基于物理方法回收光伏（PV）模块的经济回收工艺包括破碎或研磨步骤，并且在光伏模块的硅（Si）回收过程中伴随着杂质污染。先前的研究已经解决了金属污染问题，在进一步的蚀刻步骤中可以相对容易地处理金属污染。然而，在模块分离过程中，背板二氧化钛（TiO）的污染尚未被考虑。特别是后续的化学处理很难去除 TiO2 纳米颗粒。本研究提出了一种两步研磨工艺，包括干法和湿法序列，以控制直接从光伏组件回收的硅 (ReSi) 粉末的污染和尺寸。该方法通过湿法工艺过程中 Si 和 TiO 颗粒在溶剂中表现出的不同沉降速率，实现了 ReSi 中 TiO 浓度的十倍降低。此外，当前的方法无缝地建立了干磨和湿磨条件，通过优化研磨介质的比例和研磨时间来最小化 ReSi 粉末的尺寸。不同粒径的ReSi粉末作为锂离子电池负极材料进行了评估。此外，还比较了微米级和纳米级ReSi的循环性能和体积变化，以验证两步研磨的效果。与微型ReSi相比，纳米ReSi的锂离子电池容量提高了35.33%，体积膨胀率降低了57.67%。