title: Iron-Based Electrodes Meet Water-Based Preparation, Fluorine-Free Electrolyte and Binder: A Chance for More Sustainable Lithium-Ion Batteries?
abstract: Environmentally friendly and cost-effective Li-ion cells are fabricated with abundant, non-toxic LiFePO4cathodes and iron oxide anodes. A water-soluble alginate binder is used to coat both electrodes to reduce the environmental footprint. The critical reactivity of LiPF6-based electrolytes toward possible traces of H2O in water-processed electrodes is overcome by using a lithium bis(oxalato)borate (LiBOB) salt. The absence of fluorine in the electrolyte and binder is a cornerstone for improved cell chemistry and results in stable battery operation. A dedicated approach to exploit conversion-type anodes more effectively is also disclosed. The issue of large voltage hysteresis upon conversion/de-conversion is circumvented by operating iron oxide in a deeply lithiated Fe/Li2O form. Li-ion cells with energy efficiencies of up to 92 % are demonstrated if LiFePO4is cycled versus such anodes prepared through a pre-lithiation procedure. These cells show an average energy efficiency of approximately 90.66 % and a mean Coulombic efficiency of approximately 99.65 % over 320 cycles at current densities of 0.1, 0.2 and 0.3 mA cm-2. They retain nearly 100 % of their initial discharge capacity and provide an unmatched operation potential of approximately 2.85 V for this combination of active materials. No occurrence of Li plating was detected in three-electrode cells at charging rates of approximately 5C. Excellent rate capabilities of up to approximately 30C are achieved thanks to the exploitation of size effects from the small Fe nanoparticles and their reactive boundaries.
authors.affiliation: Department of Chemistry-Ångström Laboratory, Uppsala University, Box 538, 75121, Uppsala, Sweden), Fax: (+46) 018-513-548.
authors.forename: Mario
authors.initials: M
authors.lastname: Valvo
authors.affiliation: Department of Chemistry-Ångström Laboratory, Uppsala University, Box 538, 75121, Uppsala, Sweden), Fax: (+46) 018-513-548.
authors.forename: Anti
authors.initials: A
authors.lastname: Liivat
authors.affiliation: Department of Chemistry-Ångström Laboratory, Uppsala University, Box 538, 75121, Uppsala, Sweden), Fax: (+46) 018-513-548.
authors.forename: Henrik
authors.initials: H
authors.lastname: Eriksson
authors.affiliation: Department of Materials and Environmental Chemistry-Arrhenius Laboratory, Stockholm University, 10691, Stockholm, Sweden.
authors.forename: Cheuk-Wai
authors.initials: CW
authors.lastname: Tai
authors.affiliation: Department of Chemistry-Ångström Laboratory, Uppsala University, Box 538, 75121, Uppsala, Sweden), Fax: (+46) 018-513-548.
authors.forename: Kristina
authors.initials: K
authors.lastname: Edström
mesh_terms: D011211:Electric Power Supplies / Q000592:standards*; D004563:Electrochemistry; D004566:Electrodes; D004573:Electrolytes; D005290:Ferric Compounds; D005461:Fluorine; D007501:Iron; D008094:Lithium; D010710:Phosphates; D014867:Water / Q000737:chemistry*
chemical_list: D004573:Electrolytes; D005290:Ferric Compounds; C473349:LiFePO4; D010710:Phosphates; D014867:Water; C000499:ferric oxide; D005461:Fluorine; D008094:Lithium; D007501:Iron
keywords: batteries; electrolytes; energy storage; iron oxide; pseudocapacitance