Ni Zhicong, Zhang Yiyong, Zhu Bowen, Wang Yanjie, Wang Ying, Li Xue, Zhang Yingjie, Sun Shigang
National and Local Joint Engineering Laboratory for Lithium-ion Batteries and Materials Preparation Technology, Key Laboratory of Advanced Battery Materials of Yunnan Province, Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, PR China.
National and Local Joint Engineering Laboratory for Lithium-ion Batteries and Materials Preparation Technology, Key Laboratory of Advanced Battery Materials of Yunnan Province, Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, PR China.
J Colloid Interface Sci. 2022 Jan;605:223-230. doi: 10.1016/j.jcis.2021.07.108. Epub 2021 Jul 23.
The unstable electrode/electrolyte interface of the lithium metal anode is one of the reasons that induce the formation of lithium (Li) dendrites. The Li dendrites will reduce the coulombic efficiency, and even pierce the separator to cause the safety problems. Herein, a tightly bonded and uniformly distributed CuSn interface layer is formed on the surface of the Cu foam by a simple electroless plating method. The composite layer has multiple functions, such as high lithiophilicity, high carrier transport and high adaptability to mechanical strain. Based on the versatility of the CuSn interface layer, the cycle life of Cu foam is increased from 150 h to 1000 h, and the deposition overpotential is as low as 18 mV. In-situ online observation proves that the existence of composite layer can make Li metal uniformly deposited to avoid the dendrites. Furthermore, CuSn@Cu foam also shows a higher capacity retention rate (increased from 65.2% to 78.6% after 300 cycles) and a more stable rate performance when it is used in full batteries. Compared with the single function improvement strategy proposed by the current lithium metal anode research. The CuSn multifunctional composite layer modification method in this work provides a new strategy for constructing a stable electrode/electrolyte interface.
锂金属负极不稳定的电极/电解质界面是导致锂枝晶形成的原因之一。锂枝晶会降低库仑效率，甚至刺穿隔膜引发安全问题。在此，通过简单的化学镀方法在泡沫铜表面形成了紧密结合且均匀分布的CuSn界面层。该复合层具有多种功能，如高亲锂性、高载流子传输能力以及对机械应变的高适应性。基于CuSn界面层的多功能性，泡沫铜的循环寿命从150小时提高到1000小时，沉积过电位低至18毫伏。原位在线观察证明复合层的存在可使锂金属均匀沉积以避免枝晶形成。此外，CuSn@泡沫铜在全电池中使用时还表现出更高的容量保持率（300次循环后从65.2%提高到78.6%）和更稳定的倍率性能。与当前锂金属负极研究所提出的单一功能改进策略相比，本工作中的CuSn多功能复合层改性方法为构建稳定的电极/电解质界面提供了一种新策略。
