TY - JOUR

T1 - Improved Electrochemical Performance of Modified Mesocarbon Microbeads for Lithium-Ion Batteries Studied using Solid-State Nuclear Magnetic Resonance Spectroscopy

AU - Bösebeck, Katharina

AU - Chandran, C. Vinod

AU - Licht, Björn K.

AU - Binnewies, Michael

AU - Heitjans, Paul

N1 - Funding Information: We thank the Niedersächsisches Ministerium für Wissenschaft und Kultur (MWK) for the financial support of this work within Graduiertenkolleg Energiespeicher und Elektromobilität Niedersachsen (GEENI, ZN2783). We thank Kai Volgmann for technical support with the NMR measurements. We gratefully acknowledge the supply of MCMB by MTI Corporation. Publisher Copyright: © 2016 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

PY - 2016/12/1

Y1 - 2016/12/1

N2 - 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.

AB - 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.

KW - cyclic voltammetry

KW - electrochemistry

KW - graphite

KW - lithium-ion batteries

KW - nuclear magnetic resonance

UR - http://www.scopus.com/inward/record.url?scp=84992520914&partnerID=8YFLogxK

U2 - 10.1002/ente.201600211

DO - 10.1002/ente.201600211

M3 - Article

AN - SCOPUS:84992520914

VL - 4

SP - 1598

EP - 1603

JO - Energy technology

JF - Energy technology

SN - 2194-4288

IS - 12

ER -