Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7725256 | Journal of Power Sources | 2018 | 7 Pages |
Abstract
Layered Ni-rich Li[Ni0.6Mn0.2Co0.2-xMx]O2 cathode materials (xâ¯=â¯0, 0.05; Mâ¯=â¯Al, Fe, Sn) are synthesized via a co-precipitation synthesis route and the effect of dopants on the structure and electrochemical performance is investigated. All synthesized materials show a well-defined layered structure of the hexagonal α-NaFeO2 phase investigated by X-ray diffraction (XRD). Undoped LiNi0.6Mn0.2Co0.2O2 exhibits a discharge capacity of 170 mAh gâ1 in Li-metal 2032 coin-type cells. Doped materials reach lower capacities between 145 mAh gâ1 for Al and 160 mAh gâ1 for Sn. However, all doped materials prolong the cycle life by up to 20%. Changes of the lattice parameter before and after delithiation yield information about structural stability. A smaller repulsion of the transition metal layer during delithiation in the Sn-doped material leads to a smaller expansion of the unit cell, which results in enhanced structural stability of the material. The improved structural stability of Sn-doped NMC cathode active material is proven by thermal investigations with the help of Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA).
Related Topics
Physical Sciences and Engineering
Chemistry
Electrochemistry
Authors
Matthias Eilers-Rethwisch, Martin Winter, Falko Mark Schappacher,