Effect of magnesium doping on properties of lithium-rich layered oxide cathodes based on a one-step co-precipitation strategy. Issue 13 (15th March 2016)

• Record Type: Journal Article
• Authors: Yu, Ruizhi; Wang, Xianyou; Fu, Yanqing; Wang, Lianwu; Cai, Siyu; Liu, Meihong; Lu, Bing; Wang, Gang; Wang, Di; Ren, Qifang; Yang, Xiukang
• Is Part Of: Journal of materials chemistry. Volume 4:Issue 13(2016)
• Page Start: 4941
• Page End: 4951
• Publication Date: 2016-03-15
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c6ta00370b
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : A Mg-doped lithium-rich layered oxide material with a stable structure exhibits outstanding electrochemical properties for LIBs. Abstract : A Mg-doped lithium-rich layered oxide material is successfully synthesized via a co-precipitation process and a subsequent high-temperature solid state method. The chemical composition, structural characteristics and elemental distribution of the Mg-doped lithium-rich layered oxide material are investigated by inductively coupled plasma optical emission spectroscopy (ICP-OES), scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDXS). The results show that Mg is effectively and equably doped into the samples, which can replace partially Li + in the cathode material. The electrochemical properties of the Mg-doped lithium-rich layered oxide material are evaluated and compared with those of the conventional Li1.5 [Mn0.75 Ni0.25 ]O2+ δ cathode material. It can be found that the Mg-doped lithium-rich layered oxide material exhibits excellent electrochemical performance. It can deliver a high initial discharge capacity of 248.6 mA h g −1 and an improved initial coulombic efficiency of 87.9% at 0.1C with a cut-off voltage of 2.0–4.6 V. Moreover, the capacity retention reaches a relatively high value of 94.2% after 200 cycles at 0.5C. In contrast, the capacity retention of conventional Li1.5 [Mn0.75 Ni0.25 ]O2+ δ is only 59.6%. In addition, the Mg-doped lithium-rich layered oxide material also shows excellent rate capability, which can display a discharge capacity of 130.1 mA h g −1 even at 10C and a capacity retention of 92.6% after 100 cycles at 5C. The enhanced electrochemical properties of the Mg-doped lithium-rich layered oxide material could be attributed to the introduction of Mg, which can effectively mitigate the structural deterioration of the material and facilitate the diffusion coefficient of Li + during cycling.