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Preparation of a Reduced Graphene Oxide Wrapped Lithium‐Rich Cathode Material by Self‐Assembly
Author(s) -
Lim Sung Nam,
Ahn Wook,
Yeon SunHwa,
Park Seung Bin
Publication year - 2014
Publication title -
chemistry – an asian journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.18
H-Index - 106
eISSN - 1861-471X
pISSN - 1861-4728
DOI - 10.1002/asia.201402517
Subject(s) - graphene , oxide , dielectric spectroscopy , materials science , cathode , lithium (medication) , electrochemistry , chemical engineering , composite material , nanotechnology , chemistry , metallurgy , electrode , medicine , endocrinology , engineering
Abstract A lithium‐rich cathode material wrapped in sheets of reduced graphene oxide (RGO) and functionalized with polydiallyldimethylammonium chloride (PDDA) was prepared by self‐assembly induced from the electrostatic interaction between PDDA–RGO and the Li‐rich cathode material. At current densities of 1000 and 2000 mA g −1 , the PDDA–RGO sheet wrapped samples demonstrated increased discharge capacities, increasing from 125 to 155 mA h g −1 and from 82 to 124 mA h g −1 , respectively. The decreased resistance implied by this result was confirmed from electrochemical impedance spectroscopy results, wherein the charge‐transfer resistance of the pristine sample decreased after wrapping with the PDDA–RGO sheets. The PDDA–RGO sheets served as a protective layer sand as a conductive material, which resulted in an improvement in the retention capacity from 56 to 81 % after 90 cycles.