JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2021
·Vol. 32
·期 19
·23786-23797
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IF 2.478
Zhou Dengfeng,Li Junqi,Chen Chaoyi,Chen Can,Wu Hongming,Lin Fangchang,Guo Jianbing
Ruthenium doped LiNi 0.5 Mn 1.5 O 4 (LNMO) microspheres has been prepared by a simple solid-state reaction process. The as-prepared sample was characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and electrochemistry performance test. The sample shows a spinel crystal structure without RuO 2 impurity phase, and Ru doped sample crystal plane spacing increases. Combined with EDS spectrum, it indicates that the Ru ion was doped in the LNMO and distributed homogeneously. The XPS also further confirm the existence of Ru ions, and Ru has no obvious influence on Ni and Mn elements. The SEM images show that all the samples are sphere-like, with many polyhedral particles attached to the surface. When doped with 4% Ru ion, many cavities appear on the surface to form a porous structure. Electrochemical analysis confirms that the Ru-doped sample exhibits better electrochemical properties regarding discharge capacity, cycle stability, and rate performance. The 4% Ru-doped sample owns an initial discharge capacity of 125 mAh g −1 at 0.25C rate, with a capacity retention of 92% after 50 charge–discharge cycles. Moreover, at high current density (1C), Ru doped sample’s discharge capacity is 103 mAh g −1 while the original is only 86 mAh g −1 . The excellent electrochemical properties are attributed to the Ru doping that increases the interlayer spacing and reduces the charge-transfer impedance ( R ct ), which is beneficial to lithium ion-exchange.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHEMISTRY COMMUNICATIONS
·
2012
·
IF 4.859
Yunxian Qian,Yuanfu Deng,Zhicong Shi,Yubo Zhou,Quanchao Zhuang,Guohua Chen
Spinel LiMn 1.5 Ni 0.5 O 4 (LMNO) sub-micrometer-sized spheres were prepared in one step using porous MnCO 3 microspheres as a self-supporting template. The LMNO spheres were characterized by XRD , SEM and TEM. The obtained LMNO was in a well-crystallized cubic phase with little impurity. It showed high rate capability and excellent cycling stability as a cathode material for lithium ion batteries . Initial discharge capacities of 122.0, 120.3, 119.5 and 112.1 mAh g − 1 were found at 2, 3, 5 and 10C respectively with 1C being 146.7 mA g − 1 . Their capacity retentions are 92, 91, 82 and 79% respectively after 500 cycles. The as-prepared LMNO is a promising cathode material for high power and long-life lithium ion batteries .
研究领域:
材料科学
·
电化学
·
能源存储
·
无机功能材料
·
电池技术
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Seokyoung Choi,Wuliang Feng,Zhongzhu Liu,Yongyao Xia
Spinel LiMn 1.5 Ni 0.5 O 4 (LMNO) is one of the promising cathode materials for the next generation Li-ion batteries due to its voltage platform. However, the dissolution of the transition metal at high voltage is the biggest obstacle that LMNO suffers from. In this study, we successfully suppressed transition metal dissolution in LMNO by the morphology control from regular octahedron to spherical. Niobium was integrated as a dopant, which restricted the growth of (1 1 1) crystal face, and increased the indices of crystal faces by homogenizing the surface energy. By changing to a smaller surface area with spherical morphology, the contact area with the electrolyte was reduced, thus suppressing the dissolution of the Mn ion. Consequently, the niobium-doped LMNO exhibited superior rate performance, capacity retention with 74.1% at 1C after 500 cycles in half-cell, and thermal stability compared to pristine LMNO.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 21
·12549-12558
·
IF 3.361
Dengfeng Zhou,Junqi Li,Can Chen,Fangchang Lin,Hongming Wu,Jianbing Guo
An Ru-doped spinel-structured LiNi0.5Mn1.5O4 (LNMO) cathode has been prepared via a simple hydrothermal synthesis method. The as-prepared cathode is characterized via Fourier transform infrared (FTIR) spectroscopy, powder X-ray diffraction (XRD), scanning electron microscopy (SEM), laser particle size distribution analysis, X-ray photoelectron spectroscopy (XPS) and electrochemistry performance tests. The FTIR spectroscopy and XRD analyses show that the Ru-doped LNMO has a good crystallinity with a disordered Fdm space group structure. The disordered structure in the cathode increased and the LixNi1−xO impurity phase decreased when Ru addition increased. SEM shows that all samples are octahedral particles with homogeneous sizes distribution, and the particle size analysis shows that the Ru-doped samples have smaller particle size. XPS confirms the existence of Ru ions in the sample, and reveals that the Ru induce to part of Mn4+ transfers to Mn3+ in the LNMO. The electrochemical property indicated that the Ru-doped cathode exhibits better electrochemical properties in terms of discharge capacity, cycle stability and rate performance. At a current density of 50 mA g−1, the discharge specific capacity of the Ru-4 sample is 140 mA h g−1, which is much higher than that of the other samples. It can be seen from the rate capacity curves that the Ru-doped samples exhibit high discharge specific capacity, particularly at high current density.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2014
·
IF 2.538
Hang Hu,Qiang Chen,Zhanjun Chen,Hongyu Chen
To solve the major problem of interfacial side reactions between LiMn 1.5 Ni 0.5 O 4 (LMNO) and liquid electrolyte at high voltages, zirconium phosphate (ZrP) wrapped cathode material LMNO@ZrP, with different aspect of ZrP in 2 wt% and 4 wt%, have been prepared by a hydrothermal method. In particular, we focus on the distribution of ZrP on the LMNO surface to find out the optimal coating material and amount. The effects of ZrP coating layer have been investigated by comparison of the properties of the ZrP coated LMNO (LMNO@ZrP) and pristine LMNO electrodes by several electrochemical characterizations. The electrochemical impedance spectroscopy results show that LMNO@ZrP-3M-2 electrode exhibits an improved electrochemical property of suppressing the impedance increase. In the cell life test, LMNO@ZrP-3M-2 electrode shows a high capacity retention of 94.6% after 200 cycles at 55 °C.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）