title: Transition-Metal Carbodiimides as Molecular Negative Electrode Materials for Lithium- and Sodium-Ion Batteries with Excellent Cycling Properties.
abstract: We report evidence for the electrochemical activity of transition-metal carbodiimides versus lithium and sodium. In particular, iron carbodiimide, FeNCN, can be efficiently used as negative electrode material for alkali-metal-ion batteries, similar to its oxide analogue FeO. Based on (57)Fe Mössbauer and infrared spectroscopy (IR) data, the electrochemical reaction mechanism can be explained by the reversible transformation of the Fe-NCN into Li/Na-NCN bonds during discharge and charge. These new electrode materials exhibit higher capacity compared to well-established negative electrode references such as graphite or hard carbon. Contrary to its oxide analogue, iron carbodiimide does not require heavy treatments (such as nanoscale tailoring, sophisticated textures, or coating) to obtain long cycle life with current density as high as 9 A g(-1) for hundreds of charge-discharge cycles. Similar to the iron compound, several other transition-metal carbodiimides M(x)(NCN)y with M=Mn, Cr, Zn can cycle successfully versus lithium and sodium. Their electrochemical activity and performance open the way to the design of a novel family of anode materials.
authors.affiliation: Institut Charles Gerhardt de Montpellier, UMR CNRS 5253, 34095, Montpellier, France.|Réseau sur le Stockage Electrochimique de l'Energie, FR CNRS 3459, 80039, Amiens, France.
authors.forename: Moulay T
authors.identifier: http://orcid.org/0000-0003-3740-2807
authors.initials: MT
authors.lastname: Sougrati
authors.affiliation: Institut Charles Gerhardt de Montpellier, UMR CNRS 5253, 34095, Montpellier, France.|Réseau sur le Stockage Electrochimique de l'Energie, FR CNRS 3459, 80039, Amiens, France.
authors.forename: Ali
authors.identifier: http://orcid.org/0000-0001-9297-2509
authors.initials: A
authors.lastname: Darwiche
authors.affiliation: Institute of Inorganic Chemistry, RWTH Aachen University, 52056, Aachen, Germany.
authors.forename: Xiaohiu
authors.initials: X
authors.lastname: Liu
authors.affiliation: JCNS and PGI, JARA-FIT, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany.|LCIS/GREENMAT, Institute of Chemistry B6, University of Liège, 4000, Liège, Belgium.
authors.forename: Abdelfattah
authors.initials: A
authors.lastname: Mahmoud
authors.affiliation: JCNS and PGI, JARA-FIT, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany.|Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
authors.forename: Raphael P
authors.identifier: http://orcid.org/0000-0002-6138-5624
authors.initials: RP
authors.lastname: Hermann
authors.affiliation: Groupe de Physique des Matériaux, UMR CNRS 6634 - Normandie University, 76801, St Etienne du Rouvray Cedex, France.
authors.forename: Samuel
authors.initials: S
authors.lastname: Jouen
authors.affiliation: Institut Charles Gerhardt de Montpellier, UMR CNRS 5253, 34095, Montpellier, France.|Réseau sur le Stockage Electrochimique de l'Energie, FR CNRS 3459, 80039, Amiens, France.
authors.forename: Laure
authors.initials: L
authors.lastname: Monconduit
authors.affiliation: Institute of Inorganic Chemistry, RWTH Aachen University, 52056, Aachen, Germany. drons@HAL9000.ac.rwth-aachen.de.
authors.forename: Richard
authors.identifier: http://orcid.org/0000-0002-1925-9624
authors.initials: R
authors.lastname: Dronskowski
authors.affiliation: Institut Charles Gerhardt de Montpellier, UMR CNRS 5253, 34095, Montpellier, France. lorenzo.stievano@umontpellier.fr.|Réseau sur le Stockage Electrochimique de l'Energie, FR CNRS 3459, 80039, Amiens, France. lorenzo.stievano@umontpellier.fr.
authors.forename: Lorenzo
authors.identifier: http://orcid.org/0000-0001-8548-0231
authors.initials: L
authors.lastname: Stievano
keywords: batteries; carbodiimide; lithium ions; sodium ions