A Low-Cost and High-Energy Hybrid Iron-Aluminum Liquid Battery Achieved by Deep Eutectic Solvents  Leyuan Zhang, Changkun Zhang, Yu Ding, Katrina Ramirez-Meyers, Guihua Yu  Joule  DOI: 10.1016/j.joule.2017.08.013 Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 1 The Proof-of-Concept Fe-Al Hybrid Liquid Battery (A) Schematic of an Fe-Al battery based on DESs. (B) The photograph of a working Fe-Al battery (top) and its schematic of device configuration (bottom). Joule DOI: (10.1016/j.joule.2017.08.013) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 2 The Physical Properties and CVs of Various Fe DESs (A) Photograph of various Fe DESs. (B) Ionic conductivity of FeCl3·6H2O/urea/EG as a function of composition. (C) CV curves of Fe DESs at the sweeping rate of 1 mV s−1. (D) Viscosity data of FeCl3·6H2O/urea/EG as a function of temperature and composition. Joule DOI: (10.1016/j.joule.2017.08.013) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 3 The Electrochemical Performance of Fe(126) DES (A) CV curves of Fe(126) DES at different sweeping rates. (B) Linear relationships between the oxidation and reduction peak current with the square root of the sweeping rate. (C) The charge and discharge capacity with corresponding coulombic efficiency of Fe(126) catholyte when paired with Li at the current density of 0.1 mA cm−2. (D) Polarization curve (black) and corresponding specific power density (red) at room temperature. Joule DOI: (10.1016/j.joule.2017.08.013) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 4 The Electrochemical Performance of an Fe(126)-Al Battery (A) Charge/discharge profile of Fe(126)-DES/EC-DMC (1.7 M, 0.05 mL) paired with Al-DES/DCE (3.2 M, 0.1 mL) at current density of 0.1 mA cm−2. (B) The discharge voltage and corresponding power density of an Fe(126)-Al battery at various current densities. (C) Representative charge and discharge profiles over time at the current density of 0.1 mA cm−2. (D) The charge and discharge capacity with corresponding coulombic efficiency of an Fe(126)-Al battery at room temperature over cycling. Joule DOI: (10.1016/j.joule.2017.08.013) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 5 The Electrochemical Performance of an Fe(210)-Al Battery (A) The initial charge/discharge profile of Fe(210)-DES/EC-DMC (5 M, 0.03 mL) paired with Al-DES/DCE (3.2 M, 0.18 mL) at current density of 0.1 mA cm−2. (B) Polarization graph showing the discharging potential and power density at room temperature. Joule DOI: (10.1016/j.joule.2017.08.013) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 6 Ex Situ Raman Evidence for the Working Mechanism of Fe DESs (A) The Raman spectra of 120- and 110-based Fe DESs. (B–D) The Raman spectra of 210-based Fe DESs (B); the Raman spectra of original, discharged, and charged (C) Fe(126) catholyte and (D) Fe(210) catholyte. Joule DOI: (10.1016/j.joule.2017.08.013) Copyright © 2017 Elsevier Inc. Terms and Conditions

Joule DOI: (10.1016/j.joule.2017.08.013) Copyright © 2017 Elsevier Inc. Terms and Conditions