中国科学院深圳先进技术研究院唐永炳团队报道了锂离子电池微米级颗粒铝阳极中离子和电荷传输的异常尺寸效应。相关研究成果发表在2022年7月7日出版的《德国应用化学》。

铝由于其理论容量高，导电性好，自然界储量丰富，是一种很有前途的锂离子电池负极材料。

该文观察到微米级铝粉电极的异常尺寸效应。实验和理论研究表明，绝缘氧化物表面层是潜在的根源，当颗粒太小时，这会导致导电性差和容量利用率有限。此外，由于氧化层的弱极性特征，较差的电解质润湿性也解释了受阻的反应动力学。极性氨基的表面接枝被证明是改善电解质润湿性的有效策略。

该工作揭示了铝阳极的关键局限性和潜在机制，这对其实际应用至关重要。该结果对具有类似问题的其他金属阳极也有价值。

附：英文原文

Title: Unusual Size Effect in Ion and Charge Transport in Micron-sized Particulate Aluminum Anodes of Lithium-ion Batteries

Author: Chunlei Jiang, Yinyin Zheng, Doufeng Wang, Yongping Zheng, Chengde Xie, Lei Shi, Zhipeng Liu, Yongbing Tang

Issue&Volume: 2022-07-07

Abstract: Aluminum is a promising anode material for lithium-ion batteries owing to its high theoretical capacity, excellent conductivity, and natural abundance. An anomalous size effect was observed for micron-sized aluminum powder electrodes in this work. Experimental and theoretical investigations reveal that the insulating oxide surface layer is the underlying root, which leads to poor electrical conductivity and limited capacity utilization when the particle is too small. Additionally, poor electrolyte wettability also accounts for the hindered reaction kinetics due to the weak polarity feature of the oxide layer. Surface grafting of polar amino groups was demonstrated to be an effective strategy to improve electrolyte wettability. The present work revealed the critical limitations and underlying mechanisms for the aluminum anode, which is crucial for its practical application. Our results are also valuable for other metallic anodes with similar issues.

DOI: 10.1002/anie.202208370

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202208370