Electrochemically Fabricated Polypyrrole–Cobalt–Oxygen Coordination Complex as High‐Performance Lithium‐Storage Materials

Abstract

Current lithium-ion battery (LIB) technologies are all based on inorganic electrode materials, though organic materials have been used as electrodes for years. Disadvantages such as limited thermal stability and low specific capacity hinder their applications. On the other hand, the transition metal oxides that provide high lithium-storage capacity by way of electrochemical conversion reaction suffer from poor cycling stability. Here we report a novel high-performance, organic, lithium-storage material, a polypyrrole-cobalt-oxygen (PPy-Co-O) coordination complex, with high lithium-storage capacity and excellent cycling stability. Extended X-ray absorption fine structure and Raman spectroscopy and other physical and electrochemical characterizations demonstrate that this coordination complex can be electrochemically fabricated by cycling PPy-coated Co(3)O(4) between 0.0 V and 3.0 V versus Li(+)/Li. Density functional theory (DFT) calculations indicate that each cobalt atom coordinates with two nitrogen atoms within the PPy-Co coordination layer and the layers are connected with oxygen atoms between them. Coordination weakens the C-H bonds on PPy and makes the complex a novel lithium-storage material with high capacity and high cycling stability.

Intercalation and delamination of layered carbides and carbonitrides

“…The reason for this mismatch is unclear at this time. However, a similar phenomenon observed on other nano-structured electrodes was explained by assuming the excess capacity stored in a unique reversible solid electrolyte interphase [31][32][33][34][35] . More work is ongoing to understand the lithiation and delithiation mechanisms of d-MXenes, in addition to further optimization of their performance.…”

Organic Electrode Materials for Rechargeable Lithium Batteries

“…[ 209 ] Totally insoluble two-dimensional polymers of cyano-substituted phthalocyancine met with partial irreversible lithium intercalation unless shallow discharge was carefully maintained. [ 213 ] There are still sporadic studies conerning other classes of organic electrode materials for rechargeable lithium batteries. Substitution of three hydrogen atoms ( 164 ) with bromine ( 165 ) induces a large increase of discharge potential from 1.83 to 2.6 V vs Li/Li + .…”

Conductive Hydrogels as Smart Materials for Flexible Electronic Devices

“…Since then, the conductive‐hydrogel‐based electrode in lithium ion batteries has been further developed. Polypyrrole‐hydrogel‐coated TiO 2 , Si or Fe 3 O 4 nanoparticles as high‐performance Li‐ion battery electrodes also showed high gravimetric capacity and high areal capacity …”