A degradable attapulgite/polyvinyl alcohol composite separator for lithium-ion batteries based on multiple hydrogen bonds

Polyolefin separators are currently an indispensable component of lithium-ion batteries (LIBs). However, their extreme resistance to degradation-which may take centuries-poses a serious threat of “white pollution” in the upcoming large-scale wave of battery disposal. Hence, the development of biodegradable or environmentally friendly alternative separators represents the most fundamental and promising solution. In this study, a composite separator based on polyvinyl alcohol (PVA) and attapulgite (ATP), was fabricated via electrospinning. The incorporation of ATP-which possesses abundant nanochannels and excellent thermal stability-enhances the physicochemical properties of the ATP/PVA composite separator. Compared with a commercial PP separator, the LiFePO 4 /Li half-cell assembled with the ATP/PVA-2 separator exhibits a higher discharge specific capacity of 144.7 mAh·g −1 , significantly exceeding the 131.5 mAh·g −1 of the cell with a PP separator. Furthermore, the cell equipped with the ATP/PVA-2 separator demonstrates exceptional cycling stability, showing almost no capacity decay after 200 charge-discharge cycles. Additionally, the ATP/PVA composite separator exhibits outstanding degradability, completely dissolved in deionized water within 2 min and achieved complete biodegradation in natural soil within 4 months. The as-prepared ATP/PVA composite separator not only shows promising physicochemical properties but also degrades readily, making it a strong candidate as an eco-friendly alternative to conventional polyolefin separators.