Design of multifunctional interfaces on ceramic solid electrolytes for high-performance lithium-air batteries

• Published in: Green energy & environment
• Main Authors: Shi, Yunxin, Guo, Ziyang, Wang, Changhong, Gao, Mingze, Lin, Xiaoting, Duan, Hui, Wang, Yonggang, Sun, Xueliang
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2024
• Subjects: Ambient air; Composite electrolyte; Li1.5Al0.5Ge1.5(PO4)3; Li–air batteries; Polymers; Composite electrolyte; Li1.5Al0.5Ge1.5(PO4)3; Li–air batteries; Ambient air; Polymers
• ISSN: 2468-0257; 2468-0257
• DOI: 10.1016/j.gee.2024.02.010

High-energy-density lithium (Li)–air cells have been considered a promising energy-storage system, but the liquid electrolyte-related safety and side-reaction problems seriously hinder their development. To address these above issues, solid-state Li–air batteries have been widely developed. However, many commonly-used solid electrolytes generally face huge interface impedance in Li–air cells and also show poor stability towards ambient air/Li electrodes. Herein, we fabricate a differentiating surface-regulated ceramic-based composite electrolyte (DSCCE) by constructing disparately LiI-containing polymethyl methacrylate (PMMA) coating and Poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) layer on both sides of Li1.5Al0.5Ge1.5(PO4)3 (LAGP). The cathode-friendly LiI/PMMA layer displays excellent stability towards O2− and also greatly reduces the decomposition voltage of discharge products in Li–air system. Additionally, the anode-friendly PVDF-HFP coating shows low-resistance properties towards anodes. Moreover, Li dendrite/passivation derived from liquid electrolyte-induced side reactions and air/I-attacking can be obviously suppressed by the uniform and compact composite framework. As a result, the DSCCE-based Li–air batteries possess high capacity/low voltage polarization (11,836 mA h g−1/1.45 V under 500 mA g−1), good rate performance (capacity ratio under 1000 mA g−1/250 mA g−1 is 68.2%) and long-term stable cell operation (∼300 cycles at 750 mA g−1 with 750 mAh g−1) in ambient air. The differentiatingly surface-regulated ceramic-based composite electrolyte (DSCCE) is constructed and applied in Li–air batteries. Because of the antioxidative PMMA-based layer with LiI redox mediator catalyst, anode-friendly PVDF-HFP-based coating and compact/stable ceramic frameworks, the corresponding cells shows the excellent cycling life under ambient air. [Display omitted] •Differentiating surface-regulated ceramic-based composite electrolyte (DSCCE) is constructed.•LiI/PMMA-based and PVDF-HFP-based layers of DSCCE match well with air-cathode and anode, respectively.•DSCCE effectively improve electrochemical performances of Li–air battery.