scholarly journals Scalable Synthesis and Electrochemical Properties of Porous Si-CoSi2-C Composites as an Anode for Li-ion Batteries

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5397
Author(s):  
Hyungeun Seo ◽  
Hae-Ri Yang ◽  
Youngmo Yang ◽  
Kyungbae Kim ◽  
Sung Hyon Kim ◽  
...  

Si-based anodes for Li-ion batteries (LIBs) are considered to be an attractive alternative to graphite due to their higher capacity, but they have low electrical conductivity and degrade mechanically during cycling. In the current study, we report on a mass-producible porous Si-CoSi2-C composite as a high-capacity anode material for LIBs. The composite was synthesized with two-step milling followed by a simple chemical etching process. The material conversion and porous structure were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, and electron microscopy. The electrochemical test results demonstrated that the Si-CoSi2-C composite electrode exhibits greatly improved cycle and rate performance compared with conventional Si-C composite electrodes. These results can be ascribed to the role of CoSi2 and inside pores. The CoSi2 synthesized in situ during high-energy mechanical milling can be well attached to the Si; its conductive phase can increase electrical connection with the carbon matrix and the Cu current collectors; and it can accommodate Si volume changes during cycling. The proposed synthesis strategy can provide a facile and cost-effective method to produce Si-based materials for commercial LIB anodes.

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4531
Author(s):  
Mihaela-Ramona Buga ◽  
Adnana Alina Spinu-Zaulet ◽  
Cosmin Giorgian Ungureanu ◽  
Raul-Augustin Mitran ◽  
Eugeniu Vasile ◽  
...  

Porous silica-based materials are a promising alternative to graphite anodes for Li-ion batteries due to their high theoretical capacity, low discharge potential similar to pure silicon, superior cycling stability compared to silicon, abundance, and environmental friendliness. However, several challenges prevent the practical application of silica anodes, such as low coulombic efficiency and irreversible capacity losses during cycling. The main strategy to tackle the challenges of silica as an anode material has been developed to prepare carbon-coated SiO2 composites by carbonization in argon atmosphere. A facile and eco-friendly method of preparing carbon-coated SiO2 composites using sucrose is reported herein. The carbon-coated SiO2 composites were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, thermogravimetry, transmission and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy, cyclic voltammetry, and charge–discharge cycling. A C/SiO2-0.085 M calendered electrode displays the best cycling stability, capacity of 714.3 mAh·g−1, and coulombic efficiency as well as the lowest charge transfer resistance over 200 cycles without electrode degradation. The electrochemical performance improvement could be attributed to the positive effect of the carbon thin layer that can effectively diminish interfacial impedance.


Author(s):  
Partha P. Paul ◽  
Chuntian Cao ◽  
Vivek Thampy ◽  
Hans-Georg Steinrück ◽  
Tanvir R. Tanim ◽  
...  

2010 ◽  
Vol 25 (8) ◽  
pp. 1601-1616 ◽  
Author(s):  
Jordi Cabana ◽  
Christopher S. Johnson ◽  
Xiao-Qing Yang ◽  
Kyung-Yoon Chung ◽  
Won-Sub Yoon ◽  
...  

The complexity of layered-spinel yLi2MnO3·(1 – y)Li1+xMn2–xO4 (Li:Mn = 1.2:1; 0 ≤ x ≤ 0.33; y ≥ 0.45) composites synthesized at different temperatures has been investigated by a combination of x-ray diffraction (XRD), x-ray absorption spectroscopy (XAS), and nuclear magnetic resonance (NMR). While the layered component does not change substantially between samples, an evolution of the spinel component from a high to a low lithium excess phase has been traced with temperature by comparing with data for pure Li1+xMn2–xO4. The changes that occur to the structure of the spinel component and to the average oxidation state of the manganese ions within the composite structure as lithium is electrochemically removed in a battery have been monitored using these techniques, in some cases in situ. Our 6Li NMR results constitute the first direct observation of lithium removal from Li2MnO3 and the formation of LiMnO2 upon lithium reinsertion.


RSC Advances ◽  
2016 ◽  
Vol 6 (39) ◽  
pp. 32462-32466 ◽  
Author(s):  
Haihua Zhao ◽  
Wen Qi ◽  
Xuan Li ◽  
Hong Zeng ◽  
Ying Wu ◽  
...  

Alloy anodes for Li-ion batteries (LIBs) have attracted great interest due to their high capacity.


2014 ◽  
Vol 07 (04) ◽  
pp. 1430002 ◽  
Author(s):  
Liu Li ◽  
Kim Seng Lee ◽  
Li Lu

Li -rich layer-structured x Li 2 MnO 3 ⋅ (1 - x) LiMO 2 ( M = Mn , Ni , Co , etc.) materials have attracted much attention due to their extraordinarily high reversible capacity as the cathode material in Li -ion batteries. To better understand the nature of this type of materials, this paper reviews history of development of the Li -rich cathode materials, and provides in-depth study on complicated crystal structures and reaction mechanisms during electrochemical charge/discharge cycling. Despite the fabulous capability at low rate, several drawbacks still gap this type of high-capacity cathode materials from practical applications, for instance the large irreversible capacity loss at first cycle, poor rate capability, severe voltage decay and capacity fade during electrochemical charge/discharge cycling. This review will also address mechanisms for these inferior properties and propose various possible solutions to solve above issues for future utilization of these cathode materials in commercial Li -ion batteries.


Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3624
Author(s):  
Zhijie Xu ◽  
Fangxu Hu ◽  
De Li ◽  
Yong Chen

In the late 1960s, the establishment of Prigogine’s dissipative structure theory laid the foundation for the (electro)chemical oscillation phenomenon, which has been widely investigated in some electrochemical reactions, such as electro-catalysis and electro-deposition, while the electrochemical oscillation of Li-ion batteries has just been discovered in spinel Li4Ti5O12 a few years before. In this work, spinel LiCrTiO4 samples were synthesized by using a high-temperature solid-state method, characterized with SEM (Scanning electron microscope), XRD (X-ray diffraction), Raman and XPS (X-ray photoelectron spectroscopy) measurements, and electrochemically tested in Li-ion batteries to study the electrochemical oscillation. When sintering in a powder form at a temperature between 800 and 900 °C, we achieved the electrochemical oscillation of spinel LiCrTiO4 during charging, and it is suppressed in the non-stoichiometric LiCrTiO4 samples, especially for reducing the Li content or increasing the Cr content. Therefore, this work developed another two-phase material as the powder-sintered LiCrTiO4 exhibiting the electrochemical oscillation in Li-ion batteries, which would inspire us to explore more two-phase electrode materials in Li-ion batteries, Na-ion batteries, etc.


2022 ◽  
Vol 3 ◽  
Author(s):  
Andrew Stephen Leach ◽  
Alice V. Llewellyn ◽  
Chao Xu ◽  
Chun Tan ◽  
Thomas M. M. Heenan ◽  
...  

Understanding the performance of commercially relevant cathode materials for lithium-ion (Li-ion) batteries is vital to realize the potential of high-capacity materials for automotive applications. Of particular interest is the spatial variation of crystallographic behavior across (what can be) highly inhomogeneous electrodes. In this work, a high-resolution X-ray diffraction technique was used to obtain operando transmission measurements of Li-ion pouch cells to measure the spatial variances in the cell during electrochemical cycling. Through spatially resolved investigations of the crystallographic structures, the distribution of states of charge has been elucidated. A larger portion of the charging is accounted for by the central parts, with the edges and corners delithiating to a lesser extent for a given average electrode voltage. The cells were cycled to different upper cutoff voltages (4.2 and 4.3 V vs. graphite) and C-rates (0.5, 1, and 3C) to study the effect on the structure of the NMC811 cathode. By combining this rapid data collection method with a detailed Rietveld refinement of degraded NMC811, the spatial dependence of the degradation caused by long-term cycling (900 cycles) has also been shown. The variance shown in the pristine measurements is exaggerated in the aged cells with the edges and corners offering an even lower percentage of the charge. Measurements collected at the very edge of the cell have also highlighted the importance of electrode alignment, with a misalignment of less than 0.5 mm leading to significantly reduced electrochemical activity in that area.


2019 ◽  
Vol 4 (2) ◽  
pp. 105
Author(s):  
Soraya Ulfa Muzayanha ◽  
Cornelius Satria Yudha ◽  
Luthfi Mufidatul Hasanah ◽  
Adrian Nur ◽  
Agus Purwanto

<p>The use of Li-ion batteries has increased with the increasing of portable electronic media. Li-ion batteries have a life cycle hence a recycling process is needed in order to reduce the potential hazard of waste while increasing the economic value of unused battery material, especially its cathode active material. This study used Lithium Nickel Cobalt Oxide (NCA) cathode scrap to be regenerated which NCA material has high energy density and high capacity. The pretreatment process is one of the determinants in the subsequent recycling process. In this study, the effect of heating on the pretreatment process was carried out with variation temperatures of 500-800<sup>0</sup>C to obtain powder which will be recycled. The combination process of the leaching and co-precipitation was used to regenerate the cathode active material. Atomic Absorption Spectrophotometry (AAS) was performed to determine leaching efficiency using 4M H<sub>2</sub>SO<sub>4</sub> at 40<sup>0</sup>C for 3 hours. X-ray Diffraction (XRD) analysis showed that NCA material has been successfully regenerated which the diffraction peaks of NCA material was in accordance with JCPDS standards. The morphology of NCA material was tested using Scanning Electron Microscopy (SEM). Electrochemical testing uses a cylindrical battery at 2.7-4.2 Volt which the initial specific discharge capacity of the power is 62.13 mAh / g.</p>


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