Main content area

Influences of Gd3+ doping modification on the crystal microstructure and electrochemical performance of Li1.20[Mn0.52Ni0.20Co0.08]O2 as cathode for Lithium-ion batteries

Xie, Kai, Qian, Junchao, Zhou, Yuyang, Chen, Zhigang, Lin, Yun, Chen, Feng, Shen, Zigang
Powder technology 2018 v.339 pp. 838-845
X-ray diffraction, cathodes, cations, coprecipitation, electric power, electrochemistry, gadolinium, lithium batteries, microstructure, mixing, powders, scanning electron microscopy, temperature, transmission electron microscopy
The Li1.20[Mn0.52-xGdxNi0.20Co0.08]O2 (x = 0, 0.01, 0.02, 0.03) cathode materials have been synthesized by using the combination of co-precipitation with high temperature sintering method. The XRD, SEM, TEM and galvanostatic charge-discharge tests were carried out to study the influence of Gd³⁺ doping on the crystal structural, morphology and electrochemical properties of Li1.20[Mn0.52Ni0.20Ni0.08]O2. The XRD result revealed the Gd³⁺ doping modification could decrease the cation mixing degree. The galvanostatic charge-discharge tests results showed the improved electrochemical properties were obtained through the Gd³⁺ doping modification. With the increase of Gd³⁺ doping content, the capacity retentions enhanced from 88.1% to 90.3% and then decrease to 87.0% after 100 cycles with x = 0.01, 0.02 and 0.03, respectively, while the un-doped sample delivered the capacity retention of 85.1%. The Li1.20[Mn0.50Gd0.02Ni0.20Co0.08]O2 exhibited a discharge capacity of 115.5 mAh g⁻¹ at 5C rate, much larger than that (85.1 mAh g⁻¹) of the un-doped Li1.20[Mn0.52Ni0.20Co0.08]O2. The cyclic voltammetric analysis has proved that the Gd³⁺ doping modification can keep the stability of the cathode layer structure and further hold the high working voltage.