Improved Electrochemical Performance of Modified Mesocarbon Microbeads for Lithium-Ion Batteries Studied using Solid-State Nuclear Magnetic Resonance Spectroscopy

verfasst von

Katharina Bösebeck, C. Vinod Chandran, Björn K. Licht, Michael Binnewies, Paul Heitjans

Abstract

Lithium-intercalating materials such as graphite are of great interest, especially for application in lithium-ion batteries. In this work we present an investigation of the electrochemical performance of mesocarbon microbeads (MCMB) modified with copper to reveal the basic electrochemical mechanisms. Copper-modified graphite is known to have better long-term cycling behavior as well as higher capacity compared to the pristine material. Several reasons for these effects were postulated but not proven. Solid-state nuclear magnetic resonance (NMR) spectroscopy provides structural and dynamic information on lithium in ionic conductors. To elucidate the changes in structure and dynamics for the pristine and the modified material, we have employed multi-nuclear solid-state NMR spectroscopy as well as ⁷Li spin-lattice relaxation measurements and were able to clarify some reasons for the improved characteristics of copper-modified graphite compared to the pristine material, which include increased solid–electrolyte interface (SEI) formation, a facilitated diffusion of lithium ions through the SEI, and reduced moisture.

Organisationseinheit(en)

Institut für Anorganische Chemie
Institut für Physikalische Chemie und Elektrochemie

Typ

Artikel

Journal

Energy technology

Band

4

Seiten

1598-1603

Anzahl der Seiten

6

ISSN

2194-4288

Publikationsdatum

01.12.2016

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Allgemeine Energie

Ziele für nachhaltige Entwicklung

SDG 7 – Erschwingliche und saubere Energie

Elektronische Version(en)

https://doi.org/10.1002/ente.201600211 (Zugang: Offen)