An anode-free aqueous hybrid batteries enabled by in-situ Cu/Sn/Zn alloy formation on pure Cu substrate. (1st March 2023)

• Record Type: Journal Article
• Authors: Nigatu, Teshome Assefa; Bezabh, Hailemariam Kassa; Jiang, Shi-Kai; Taklu, Bereket Woldegbreal; Nikodimos, Yosef; Yang, Sheng-Chiang; Wu, She-Huang; Su, Wei-Nien; Yang, Chun-Chen; Hwang, Bing Joe
• Is Part Of: Electrochimica acta. Volume 443(2023)
• Publication Date: 2023-03-01
• Subjects: Anode-free -- Aqueous batteries -- Hybrid electrolyte -- Alloy -- Additive; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2023.141883
• Languages: English
• ISSNs: 0013-4686

Abstract

Highlights: The E/C ratio, a quotient of capacities, is analyzed for anode-free batteries (Cu||LFP). SnBr2 results in the in-situ formation of Cu/Sn/Zn alloy and uniform zinc deposition. Average coulombic efficiency about 99.13% after 100 cycles is achieved Rechargeable aqueous anode-free hybrid battery shows excellent performance. An anode-free hybrid battery with increased energy density is demonstrated. Abstract: Zn-based rechargeable aqueous battery attracts attention due to its simplicity and benignity. Here, we propose an anode-free aqueous hybrid system with 4 M ZnSO4 and 2 M Li2 SO4 in 10% DME. Since the electrolyte is the only source of Zn, the capacity ratio between Zn salts and the cathode is also evaluated to achieve a suitable formulation of the electrolyte composition. To improve the Zn nucleation and densify the deposition, we include an additive SnBr2 to initiate the in-situ formation of Cu/Sn/Zn alloy on the surface of the Cu current collector. The effects of the SnBr2 additive on the Zn deposition, stripping, and the Cu/Sn/Zn alloy formation was investigated and characterized. SEM, cross-sectional analysis by Focused ion beam (FIB), and in-situ transmission X-ray microscope (TXM) all confirm the more uniform and dense deposition of Zn on Cu under the assistance of SnBr2 . The anode-free hybrid aqueous Cu||LFP full cell achieves 99.1% average coulombic efficiency with relatively good capacity retention (35.2%) after 100 cycles by adding SnBr2 in the hybrid electrolyte with an optimized electrolyte/cathode capacity ratio of 9.45. The proposed anode-free approach is hoped to help the sustainable development of an aqueous battery system with high energy density and environmental benignity. Graphical abstract: Image, graphical abstract