Li2Ni0.2Co1.8O4 having a spinel framework as a zero-strain positive electrode material for lithium-ion batteries

Autor: Kensuke Kajikawa, Kingo Ariyoshi, Yuki Orikasa, Yusuke Yamada
Rok vydání: 2019
Předmět:
Zdroj: Journal of Materials Chemistry A. 7:13641-13649
ISSN: 2050-7496
2050-7488
DOI: 10.1039/c9ta03191j
Popis: Zero-strain insertion materials are ideal electrode materials for lithium-ion batteries because they do not undergo dimensional change during lithium insertion and extraction. Herein, a zero-strain insertion material, Ni-substituted Li2Co2O4 (Li2Ni0.2Co1.8O4) having a spinel framework, was synthesized and characterized to study the zero-strain mechanism. The change in the lattice dimensions of Li2Ni0.2Co1.8O4 during lithium extraction was very small (only 0.1%), confirming that Li2Ni0.2Co1.8O4 is a zero-strain insertion material. It had a flat voltage profile at 3.5 V with a reversible capacity of 100 mA h g−1, which was quite different from the voltage profile of LiCoO2 having a layered structure. Detailed structural analysis by X-ray absorption spectroscopy revealed that there was no dimensional change because the changes in two crystallographic factors, contraction of the Co–O bond and distortion of the oxygen sublattice, cancelled out. The zero-strain lithium-ion battery combined with Li2Ni0.2Co1.8O4 and Li[Li1/3Ti5/3]O4 showed good cyclability.
Databáze: OpenAIRE