Constructing Multifunctional Interphase between Li1.4Al0.4Ti1.6(PO4)3 and Li Metal by Magnetron Sputtering for Highly Stable Solid‐State Lithium Metal Batteries

• Published in: Advanced energy materials 2019-09, Vol.9 (34), p.n/a
• Main Authors: Hao, Xiaoge, Zhao, Qiang, Su, Shiming, Zhang, Shiqi, Ma, Jiabin, Shen, Lu, Yu, Qipeng, Zhao, Liang, Liu, Yong, Kang, Feiyu, He, Yan‐Bing
• Format: Article
• Language: English
• Subjects: Dendritic structure; Electrolytes; Flux density; High impedance; interface resistance; Interface stability; Ion currents; Li metal batteries; Li1.4Al0.4Ti1.6(PO4)3; Lithium; Lithium batteries; Lithium-ion batteries; Magnetron sputtering; multifunctional interphase; Photovoltaic cells; Short circuits; Solid electrolytes; Surface stability; Zinc oxide
• ISSN: 1614-6832; 1614-6840
• DOI: 10.1002/aenm.201901604

Due to high ionic conductivity and low cost, Li1.4Al0.4Ti1.6(PO4)3 (LATP) has emerged as a promising solid‐state electrolyte for next‐generation lithium (Li) metal solid‐state batterie with high safety performance and energy density. However, the extremely high impedance and surface instability of LATP with Li metal retard its practical application. Herein, a novel method is proposed to construct an ultrathin ZnO layer that is tightly coated on the LATP pellets, surface (ZnO@LATP) via magnetron sputtering, which in situ reacts with Li to form a low electronic conductivity and multifunctional solid electrolyte interphase (SEI). The formed SEI can not only effectively lower the interfacial resistance, but also overcome the side reactions of LATP with the Li metal anode and suppress the Li dendrite growth. Specifically, the interface resistance decreases from 80 554 to 353 Ω and the overpotential reduces from 1 V to 20 mV. As a result, the Li/ZnO@LATP@ZnO/Li symmetric batteries can stably cycle for more than 2000 h without short circuit at 0.05 mA cm−2 and Li/ZnO@LATP/LiFePO4 batteries show excellent cycle stability for 200 cycles at 0.1 C. This work highlights the significance of multifunctional interphase between LATP and Li metal for improvement of interfacial impedance and instability. A novel method is proposed to construct a stable multifunctional interphase between Li1.4Al0.4Ti1.6(PO4)3 and Li metal via magnetron sputtering. The interphase formed by the in situ reaction of ZnO with Li metal with low ionic conductivity not only reduces the interfacial impedance, but also suppresses the continuous side reactions of Li1.4Al0.4Ti1.6(PO4)3 with Li metal and the Li dendrite growths.