Skip to Content
Merck

Polytype and stacking faults in the Li2CoSiO4 Li-ion battery cathode.

Chemistry (Weinheim an der Bergstrasse, Germany) (2014-10-10)
Quang Duc Truong, Murukanahally Kempaiah Devaraju, Yoshikazu Sasaki, Hiroshi Hyodo, Itaru Honma
ABSTRACT

Atomic-resolution imaging of the crystal defects of cathode materials is crucial to understand their formation and the correlation between the structure, electrical properties, and electrode performance in rechargeable batteries. The polytype, a stable form of varied crystal structure with uniform chemical composition, holds promise to engineer electronic band structure in nanoscale homojunctions.1-3 Analyzing the exact sites of atoms and the chemistry of the boundary in polytypes would advance our understanding of their formation and properties. Herein, the polytype and stacking faults in the lithium cobalt silicates are observed directly by aberration-corrected scanning transmission electron microscopy. The atomic-scale imaging allows clarification that the polytype is formed by stacking of two different close-packed crystal planes in three-dimensional space. The formation of the polytype was induced by Li-Co cation exchange, the transformation of one phase to the other, and their stacking. This finding provides insight into intrinsic structural defects in an important Li2 CoSiO4 Li-ion battery cathode.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Ethanol, tested according to Ph. Eur.
Sigma-Aldrich
Ethyl alcohol, Pure, 200 proof, ACS reagent, ≥99.5%
Sigma-Aldrich
Ethyl alcohol, Pure 200 proof, for molecular biology
Sigma-Aldrich
Ethanol, for residue analysis
Sigma-Aldrich
Ethyl alcohol, Pure, 200 proof, meets USP testing specifications
Sigma-Aldrich
Ethanol, BioUltra, for molecular biology, ≥99.8%, (absolute alcohol, without additive, A15 o1)
Sigma-Aldrich
Ethyl alcohol, Pure, 190 proof, ACS spectrophotometric grade, 95.0%
Sigma-Aldrich
Oleylamine, technical grade, 70%
Sigma-Aldrich
Ethanol, purum, fine spirit, denaturated with 4.8% methanol, F25 METHYL1, ~96% (based on denaturant-free substance)
Sigma-Aldrich
Ethanol, purum, absolute ethanol, denaturated with 4.8% isopropanol, A15 IPA1, ≥99.8% (based on denaturant-free substance)
Sigma-Aldrich
Ethanol, purum, absolute ethanol, denaturated with 2% 2-butanone, A15 MEK1, ≥99.8% (based on denaturant-free substance)
SAFC
Oleylamine, ≥98% (primary amine)
Supelco
Ethanol solution, certified reference material, 2000 μg/mL in methanol
Supelco
Water, for HPCE, for luminescence, suitable for UV/Vis spectroscopy
Sigma-Aldrich
E-Toxate Water, endotoxin, free
Sigma-Aldrich
Cobalt(II) chloride hexahydrate, suitable for plant cell culture
Sigma-Aldrich
Water, PCR Reagent
Supelco
Water, for TOC analysis
USP
Dehydrated Alcohol, United States Pharmacopeia (USP) Reference Standard
Supelco
Dehydrated Alcohol, Pharmaceutical Secondary Standard; Certified Reference Material
Sigma-Aldrich
Water, sterile-filtered, BioReagent, suitable for cell culture
Sigma-Aldrich
Water, tested according to Ph. Eur.
Sigma-Aldrich
Water, for cell biology, sterile ultrafiltered
Sigma-Aldrich
Water, HPLC Plus
Sigma-Aldrich
Water, for embryo transfer, sterile-filtered, BioXtra, suitable for mouse embryo cell culture
Sigma-Aldrich
Water, Deionized
Sigma-Aldrich
Water, BioPerformance Certified
Sigma-Aldrich
Water, Nuclease-Free Water, for Molecular Biology
Supelco
Water, suitable for ion chromatography
Sigma-Aldrich
Water, for molecular biology, sterile filtered