An impressive approach to solving the ongoing stability problems of LiCoPO4 cathode: Nickel oxide surface modification with excellent core-shell principle

作者：Ornek Ahmet^*

来源：Journal of Power Sources, 2017, 356: 1-11.

DOI：10.1016/j.jpowsour.2017.04.074

• Li-ion batteries
• Cathode material
• Lithium cobalt phosphate
• Nickel oxide coating
• Core-shell structure

Nanoscale and NiO-coated LiCoPO4 cathode materials were prepared for the first time by a newly designed three-step synthesis route, which is a combined technique including advantages of the StOber, hydro thermal and microwave synthesis methods. Using this extraordinary technique, LiCoPO4 particles are coated with a thin NiO layer with a perfect core-shell morphology and the technique's positive contribution to electrochemistry is elucidated in detail. The samples are interpreted using opto-analytical techniques and galvanostatic charge-discharge tests. The high-resolution transmission electron microscopy analysis proves that this well-elaborated technique makes it possible to achieve a continuous NiO surface coverage of 8-10 nm, a result that contributes towards solving the chronic electrochemical problems of 4.8 V cathode material. Our data reveal that NiO-coated LiCoPO4 cathode demonstrates superior cycle stability and specific capacity at relatively low rates. The 2.5% wt. NiO-coated cathode exhibits the best electrochemical property, which reaches a discharge capacity of 159 mAh g(-1), at 0.1 C current rate and shows almost 85% capacity retention after 80 charge-discharge cycles. It therefore achieves partial success in improving the electrochemical properties of the LiCoPO4 cathode material, which is especially crucial for energy storage to be applied in electric vehicles and plug-in hybrid electric applications.

• 出版日期2017-6-15