scholarly journals Improved Capacity Retention of SiO2-Coated LiNi0.6Mn0.2Co0.2O2 Cathode Material for Lithium-Ion Batteries

2019 ◽  
Vol 9 (18) ◽  
pp. 3671 ◽  
Author(s):  
Xiaoxue Lu ◽  
Ningxin Zhang ◽  
Marcus Jahn ◽  
Wilhelm Pfleging ◽  
Hans J. Seifert

Surface degradation of Ni-enriched layered cathode material Li[Ni0.6Mn0.2Co0.2]O2 (NMC622) is the main reason that leads to large capacity decay during long-term cycling. In the frame of this research, an amorphous SiO2 coating was applied onto the surface of the commercially available NMC622 powder by a wet coating process, through the condensation reaction of tetraethyl orthosilicate. The chemical composition of the coating layer was analyzed by inductively-coupled plasma. The morphology was studied by scanning electron microscopy and transmission electron microscopy. Electrochemical properties, including cyclic voltammetry, galvanostatic cycling, and rate capability measurements in a half-cell configuration, were tested to compare the electrochemical behavior of the non-coated and coated NMC622 materials. It is shown that the rate performance of the NMC622 materials is not affected by the coating layer. After 700 cycles in the range of 3.0–4.3 V at 2 C discharge, the cells with SiO2-coated NMC622 materials retained 80% of their initial capacity, which is higher than the uncoated ones (74%). Physicochemical characterizations, e.g., XRD and SEM, were performed post-mortem to reveal the stabilizing mechanism of the SiO2-coated NMC622 electrodes after long-term cycling. Based on these results, this is due to the shielding effect of the coating between the NMC622 particle surface and the liquid electrolyte, along with its scavenging effect on HF. SiO2 coating is therefore a facile surface modification method that results in potentially significant enhancement of the cyclic stability of Ni-rich NMC materials.

Ionics ◽  
2020 ◽  
Vol 27 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Chao Chen ◽  
Quanqi Chen ◽  
Yanwei Li ◽  
Jianwen Yang ◽  
Bin Huang ◽  
...  

2021 ◽  
Vol 21 (3) ◽  
pp. 1500-1506
Author(s):  
Xiaoyue Cui ◽  
Zhiyuan Tang ◽  
Xiaokai Ma ◽  
Ji Yan

Carbon-coated lithium vanadium phosphate cathode materials were successfully prepared via an ultra-fast microwave irradiation route in 5 min with using activated carbon as the microwave adsorbent. We aimed to utilize this ultra-fast and facile route to shorten the synthesis procedure for obtaining Li3V2(PO4)3/C cathode material with superior rate capability. To characterize the intrinsic crystal structure and exterior architecture morphology of targeted material, X-ray diffraction pattern (XRD), scanning electron microscopy (SEM) in combined with transmission electron microscopy (TEM) were applied in experiment. The role of microwave irradiation treatment time in affecting the crystalline structure and related lithium-storage electrochemical performance is also investigated in detail. For the optimal Li3V2(PO4)3/C material, it delivered a specific discharge capacity of 110.1 mAh g−1 at a 0.2 C charging/discharging rate while hold a superior cycling stability over 50 cycles when tested at a 1 C rate. The ultra-fast synthesis route should pave a new way to save the energy in the preparation of phosphate-based electroactive cathode material.


2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Yuxin Ma ◽  
Ping Cui ◽  
Dan Zhan ◽  
Bing Gan ◽  
Youliang Ma ◽  
...  

The graphene oxide-coated SnO2-Li1/3Co1/3Mn1/3O2 (GO-SnO2-NCM) cathode material was successfully synthesized via a facile wet chemical method. The pristine NCM and GO-SnO2-NCM were characterized by X-ray diffraction, scanning electron microscopy, energy-dispersive spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The results showed that the double-coating layer did not destroy the NCM crystal structure, with multiple nano-SnO2 particles and GO uniformly covering the NCM surface. Electrochemical tests indicated that GO-SnO2-NCM exhibited excellent cycling performance, with 90.7% capacity retention at 1 C after 100 cycles, which was higher than 74.3% for the pristine NCM at the same cycle. The rate capability showed that the double-coating layer enhanced surface electronic–ionic transport. Electrochemical impedance spectroscopy results confirmed that the GO-SnO2-coating layer effectively suppressed the increased electrode polarization and charge transfer resistance during cycling.


2018 ◽  
Vol 6 (29) ◽  
pp. 14155-14161 ◽  
Author(s):  
Weiwei Sun ◽  
Yujie Li ◽  
Yumin Liu ◽  
Qingpeng Guo ◽  
Shiqiang Luo ◽  
...  

In this work, we have successfully synthesized hierarchically porous waxberry-like LiNi0.5Mn1.5O4 spheres comprising interpenetrating nanograins, and this material demonstrates an excellent rate capability and long-term cyclic stability.


2017 ◽  
Vol 5 (30) ◽  
pp. 15669-15675 ◽  
Author(s):  
Zhen Chen ◽  
Dongliang Chao ◽  
Jilei Liu ◽  
Mark Copley ◽  
Jianyi Lin ◽  
...  

In this work is reported the successful synthesis of 1D nanobar-like LiNi0.4Co0.2Mn0.4O2 (N-NCM), preferentially exposing the {010} electrochemically active facets.


Nano Research ◽  
2021 ◽  
Author(s):  
Qiang Guo ◽  
Wei Deng ◽  
Shengjie Xia ◽  
Zibo Zhang ◽  
Fei Zhao ◽  
...  

AbstractUncontrollable dendrite growth resulting from the non-uniform lithium ion (Li+) flux and volume expansion in lithium metal (Li) negative electrode leads to rapid performance degradation and serious safety problems of lithium metal batteries. Although N-containing functional groups in carbon materials are reported to be effective to homogenize the Li+ flux, the effective interaction distance between lithium ions and N-containing groups should be relatively small (down to nanometer scale) according to the Debye length law. Thus, it is necessary to carefully design the microstructure of N-containing carbon materials to make the most of their roles in regulating the Li+ flux. In this work, porous carbon nitride microspheres (PCNMs) with abundant nanopores have been synthesized and utilized to fabricate a uniform lithiophilic coating layer having hybrid pores of both the nano- and micrometer scales on the Cu/Li foil. Physically, the three-dimensional (3D) porous framework is favorable for absorbing volume changes and guiding Li growth. Chemically, this coating layer can render a suitable interaction distance to effectively homogenize the Li+ flux and contribute to establishing a robust and stable solid electrolyte interphase (SEI) layer with Li-F, Li-N, and Li-O-rich contents based on the Debye length law. Such a physical-chemical synergic regulation strategy using PCNMs can lead to dendrite-free Li plating, resulting in a low nucleation overpotential and stable Li plating/stripping cycling performance in both the Li‖Cu and the Li‖Li symmetric cells. Meanwhile, a full cell using the PCNM coated Li foil negative electrode and a LiFePO4 positive electrode has delivered a high capacity retention of ∼ 80% after more than 200 cycles at 1 C and achieved a remarkable rate capability. The pouch cell fabricated by pairing the PCNM coated Li foil negative electrode with a NCM 811 positive electrode has retained ∼ 73% of the initial capacity after 150 cycles at 0.2 C.


2010 ◽  
Vol 17 (01) ◽  
pp. 51-58 ◽  
Author(s):  
JEONG-HUN JU ◽  
YOUNG-MIN CHUNG ◽  
YU-RIM BAK ◽  
MOON-JIN HWANG ◽  
KWANG-SUN RYU

Carbon nano-coated LiNi 0.8 Co 0.15 Al 0.05 O 2/ C (LNCAO/C) cathode-active materials were prepared by a sol–gel method and investigated as the cathode material for lithium ion batteries. Electrochemical properties including the galvanostatic charge–discharge ability and cyclic voltammogram behavior were measured. Cyclic voltammetry (2.7–4.8 V) showed that the carbon nano-coating improved the "formation" of the LNCAO electrode, which was related to the increased electronic conductivity between the primary particles. The carbon nano-coated LNCAO/C exhibited good electrochemical performance at high C -rate. Also, the thermal stability at a highly oxidized state of the carbon nano-coated LNCAO was remarkably enhanced. The carbon nano-coating layer can serve as a physical and/or (electro-)chemical protection shell for the underlying LNCAO, which is attributed to an increase of the grain connectivity (physical part) and also to the protection of metal oxide from chemical reactions (chemical part).


2015 ◽  
Vol 3 (43) ◽  
pp. 21478-21485 ◽  
Author(s):  
Qiang Liu ◽  
Dongxue Wang ◽  
Xu Yang ◽  
Nan Chen ◽  
Chunzhong Wang ◽  
...  

The HRTEM image and long-term cycle life with capacity retentions of 70% and 50% over 1000 and 3000 cycles at 10C and 30C rates, respectively.


2011 ◽  
Vol 04 (03) ◽  
pp. 299-303 ◽  
Author(s):  
ZHUO TAN ◽  
PING GAO ◽  
FUQUAN CHENG ◽  
HONGJUN LUO ◽  
JITAO CHEN ◽  
...  

A multicomponent olivine cathode material, LiMn0.4Fe0.6PO4 , was synthesized via a novel coprecipitation method of the mixed transition metal oxalate. X-ray diffraction patterns indicate that carbon-coated LiMn0.4Fe0.6PO4 has been prepared successfully and that LiMn0.4Fe0.6PO4/C is crystallized in an orthorhombic structure without noticeable impurity. Homogeneous distribution of Mn and Fe in LiMn0.4Fe0.6PO4/C can be observed from the scanning electron microscopy (SEM) and the corresponding energy dispersive X-ray spectrometry (EDS) analysis. Hence, the electrochemical activity of each transition metal in the olivine synthesized via coprecipitation method was enhanced remarkably, as indicated by the galvanostatic charge/discharge measurement. The synthesized LiMn0.4Fe0.6PO4/C exhibits a high capacity of 158.6 ± 3 mAhg-1 at 0.1 C, delivering an excellent rate capability of 122.6 ± 3 mAhg-1 at 10 C and 114.9 ± 3 mAhg-1 at 20 C.


2019 ◽  
Vol 45 (3) ◽  
pp. 3177-3185 ◽  
Author(s):  
Meng Wang ◽  
Yongqiang Gong ◽  
Yijie Gu ◽  
Yunbo Chen ◽  
Lin Chen ◽  
...  

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