Cao Li, Zheng Min, Wang Jingbo, Li Songyuan, Xu Jiejie, Xiao Rongshi, Huang Ting
High-Power and Ultrafast Laser Manufacturing Lab, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing, 100124, China.
ACS Nano. 2022 Oct 25;16(10):17220-17228. doi: 10.1021/acsnano.2c07829. Epub 2022 Oct 6.
Nanosized alloy-type materials (Si, Ge, Sn, etc.) present superior electrochemical performance in rechargeable batteries. However, they fail to guarantee cycling capacity and stability under high mass loading required by industrial applications due to low electric contact and adhesive strength, which has long been a challenge. This work proposes a rational design for an alloy-type anode via facile and versatile laser microcladding and dealloying. The proposed anode features a large-area porous network composed of continuous nano-ligaments, which consist of evenly distributed nanosized alloy-type material metallurgically bonded with conductive material. The fabrication of the structure is validated using Ge-Cu and Sn-Cu anodes, both exhibiting enhanced cycling stability at high areal capacity and rate performance in lithium-ion batteries. The enhancement is attributed to the structural features, which contribute to lithiation-delithiation stability and intact electron/Li ion transference path, as verified by in situ and ex situ transmission electron microscopy observations. More importantly, the critical solidification conditions of laser microcladding are provided by a multiphysics simulation, allowing for a thorough understanding of the structural formation mechanism. The study provides a possible approach to improve mass loading and performance of an alloy-type anode for practical application.
纳米合金型材料（硅、锗、锡等）在可充电电池中表现出卓越的电化学性能。然而，由于电接触和粘结强度低，它们无法在工业应用所需的高质量负载下保证循环容量和稳定性，这长期以来一直是一个挑战。这项工作通过简便且通用的激光微熔覆和脱合金工艺，提出了一种合金型阳极的合理设计方案。所提出的阳极具有由连续纳米韧带组成的大面积多孔网络，这些纳米韧带由与导电材料冶金结合的均匀分布的纳米合金型材料构成。使用锗 - 铜和锡 - 铜阳极验证了该结构的制造，二者在锂离子电池中均在高面积容量和倍率性能下表现出增强的循环稳定性。这种增强归因于结构特征，原位和非原位透射电子显微镜观察证实，这些特征有助于锂化 - 脱锂稳定性以及完整的电子/锂离子传输路径。更重要的是，通过多物理场模拟提供了激光微熔覆的关键凝固条件，从而能够深入理解结构形成机制。该研究为实际应用中提高合金型阳极的质量负载和性能提供了一种可能的方法。
