Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5459643 | Journal of Alloys and Compounds | 2017 | 14 Pages |
Abstract
P2-type Na0.66Ni0.33Mn0.67âxMoxO2 (x = 0, 0.03, 0.05, 0.07) were prepared using a conventional solid state method and for the first time developed as promising cathode materials for sodium-ion batteries. The XRD patterns show that Mo6+ ions are successfully incorporated into the lattice of the Na-Ni-Mn-O system and the P2-type structure remains unchanged after substitution. The introduction of Mo6+ in the Na-Ni-Mn-O system can significantly improve capacity retention compared to the unsubstituted material during cycling. In addition, an additional charge/discharge profile can be observed between 3.0 and 3.2 V for Mo-substituted samples, demonstrating that Na+/vacancy ordering can be suppressed during sodium insertion/extraction. Na0.66Ni0.33Mn0.62Mo0.05O2 can deliver an initial capacity of 112 mAhgâ1 at 34 mAgâ1 with a high average voltage of 3.6 V and a capacity retention of 87% after 50 cycles. EIS measurements demonstrate that Mo-substitution is an effective way to hinder the increase of inter-particle contact resistance by suppressing any possible irreversible phase transformation found at low sodium contents.
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
Jiale Sun, Jianxing Shen, Tailin Wang,