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Electrochemical evaluation of Pb, Ag, and Zn cyanamides/carbodiimides

DOI: 10.1021/acsomega.8b02748 DOI Help

Authors: Jeethu Jiju Arayamparambil (ICGM, Univ. Montpellier, CNRS) , Markus Mann (RWTH Aachen University) , Xiaohui Liu (RWTH Aachen University) , Maria Alfredsson (University of Kent) , Richard Dronskowski (RWTH Aachen University) , Lorenzo Stievano (ICGM, Univ. Montpellier, CNRS; Alistore European Research Institute, CNRS; Réseau sur le Stockage Electrochimique de l’Energie) , Moulay Tahar Sougrati (ICGM, Univ. Montpellier, CNRS; Alistore European Research Institute, CNRS; Réseau sur le Stockage Electrochimique de l’Energie)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Acs Omega , VOL 4 , PAGES 4339 - 4347

State: Published (Approved)
Published: February 2019

Open Access Open Access

Abstract: PbNCN, Ag2NCN, and ZnNCN were tested as negative electrode materials for Li-ion batteries. A thorough analysis of the electrochemical mechanism by X-ray diffraction and X-ray absorption spectroscopy showed that, unlike transition metal carbodiimides, these compounds react with lithium via a two-step reaction, starting with conversion followed by alloying. The conversion reaction is highly irreversible for the three compounds, whereas the reversibility of the alloying reaction depends on the metal, that is, highly irreversible for PbNCN and Ag2NCN which contain the cyanamide group (N≡C–N2–) and more reversible for ZnNCN containing carbodiimide (−N═C═N–). In the case of the more covalent, cyanamide-type PbNCN and Ag2NCN, the conversion reaction occurs at a higher voltage compared to the more ionic, carbodiimide-type ZnNCN, correlated with the nature of bonding in the NCN group and in the phases themselves. Compared to transition metal carbodiimides, these materials show rather low performance, with no improvement in capacity as it would have been expected from the combination of conversion and alloying.

Subject Areas: Chemistry, Energy, Materials


Instruments: B18-Core EXAFS

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