scholarly journals Understanding the electrochemical performance of LiNi0. 5Mn1.5O4 coated with Yttria and distributed over graphene nanosheets as cathode in li-ion batteries

2021 ◽  
Author(s):  
Hanan Abdurehman Tariq ◽  
Zawar Alam Qureshi ◽  
Jeffin James Abraham ◽  
Shakoor Abdul ◽  
Siham Alqaradawi ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Electrode Materials ◽  
Graphene Nanosheets ◽  
Lithium Ion ◽  
Precipitation Method ◽  
Oxide Coatings ◽  
Material Synthesis ◽  
Active Particles ◽  
Co Precipitation ◽  
Synthesis Approach

LiNi0.5Mn1.5O4 is a promising cathode material for lithium-ion batteries with a high-voltage spinel structure. A microwave-assisted chemical co-precipitation method was used to synthesize Y2O3 coated quasi-spheres of LiNi0.5Mn1.5O4. The coating of Y2O3 and subsequent wrapping of quasi-spheres in graphene nanosheets does not alter the volume or promote the formation of unwanted phases. TGA analysis shows high thermal stability in the material. The material has an initial capacity of 133 mAh g−1 at C/10 with a retention of 98% after 100 cycles. In addition, cathode samples show a good capacity of 132 g−1 after 20 cycles at higher temperatures (55 °C). Oxide coatings protect the particles from ionic leaching but limit the electrical conductivity of the materials. However, graphene enhances the conductivity of the synthesized material and wraps active particles in a conductive channel. Due to the synergistic design of the material and the robust manufacturing technique, parasitic reactions are suppressed without affecting the electrical conductivity. To increase their cyclic performance, the suggested material synthesis approach may successfully be applied to various electrode materials.

Increasing the Electrical Conductivity of Layered Double Hydroxides by Intercalation of Ionic Liquids

2018 ◽  
Vol 941 ◽  
pp. 2209-2213
Author(s):  
Erica Ciotta ◽  
Roberto Pizzoferrato ◽  
Maria Luisa Di Vona ◽  
Ivan Vito Ferrari ◽  
Maria Richetta ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Ionic Liquids ◽  
Ionic Conductivity ◽  
Layered Double Hydroxides ◽  
Lithium Ion ◽  
Composite Membranes ◽  
Precipitation Method ◽  
Anionic Clays ◽  
Co Precipitation ◽  
Double Hydroxides

Layered double hydroxides (LDHs) are anionic clays composed by host layers of positively charged metal hydroxide, in which anions are intercalated to neutralize the charge of the positive layers. Because of the positive charge of the structure and because of their properties of anion exchanges, different anions can be intercalated into the structure. In recent years the ionic conductivity of LDHs was studied for use as the anode material in lithium-ion batteries or PVA/LDH hybrid membranes for fuel cells. However, such studies have reported very low values of the electrical conductivity that is less than 10-3 S cm-1 near room temperature. However, the ion conductivities of LDHs depends on the intercalated anion species and may be affected by difference in the synthesis condition. Moreover, the anion conductivity increases with increasing interlayer distance and as more water is adsorbed by LDH. Within this framework, we have intercalated two ionic liquids, tetramethylammonium hydroxide (TMAH) and 1-buthyl-3-methylimidazolium hydrogen sulfate (Bmim-HSO4) in the interlamellar space with the purpose of increasing the ionic conductivity and decreasing the dependence from the water content. LDH was prepared using the co-precipitation method with controlled pH. The introduction of IL was performed by the intercalation methods. The increase of conductivity was around an order of magnitude in the case of Bmim-HSO4. The LDH-IL can be an interesting material to prepare composite membranes for electrochemical applications.

EFFECT OF NANOSIZED TiO2 POWDER ON PREPARATION AND PROPERTIES OF Ag-BASED ELECTRODE MATERIALS

2004 ◽  
Vol 03 (06) ◽  
pp. 829-837
Author(s):  
SOON-JONG JEONG ◽  
JUNG-HYUK KOH ◽  
DONG-YOON LEE ◽  
JAE-SEOK LEE ◽  
MUN-SU HA ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Bonding Strength ◽  
Electrode Materials ◽  
Precipitation Process ◽  
Nano Oxide ◽  
Diffusion Controlled ◽  
State Diffusion ◽  
Acid Reaction ◽  
Co Precipitation ◽  
Mechanical Bonding

This study presents the synthesis of nano-oxide-added Ag/Pd powders and its properties tolerable at temperatures above 1100°C for an electrode material utilized in multilayer ceramic devices. The powders of xAg/yPd powder around core cell TiO 2 were formed in a co-precipitation process of Ag and Pd in nano-oxide-dispersed solution, where Ag and Pd precursors are melted in HNO 3 acid. Reaction between ceramic and electrode layers with nanoparticle oxide powder allows internal stress to reduce and mechanical bonding strength to increase due to anchor effect. The densification of the nano-oxide-added electrode paste followed the TiO 2 solid state diffusion-controlled mechanism upon sintering process. The mechanical bonding strength and electrical conductivity were measured after sintering the electrode-printed sheets. As a result, very high adhesive strength over the piezoelectric ceramics' fracture strength and good electrical conductivity of more than 104/Ωcm could be obtained in the multilayer ferroelectric structure which is a form of stacking ceramics layer and electrode layer containing nanoparticles.

scholarly journals Understanding the Stabilizing Effects of Nanoscale Metal Oxide and Li–Metal Oxide Coatings on Lithium-Ion Battery Positive Electrode Materials

2021 ◽  
Vol 13 (36) ◽  
pp. 42773-42790
Author(s):  
Zahra Ahaliabadeh ◽  
Ville Miikkulainen ◽  
Miia Mäntymäki ◽  
Seyedabolfazl Mousavihashemi ◽  
Jouko Lahtinen ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Lithium Ion Battery ◽  
Electrode Materials ◽  
Lithium Ion ◽  
Positive Electrode ◽  
Oxide Coatings ◽  
Metal Oxide Coatings ◽  
Positive Electrode Materials

Graphene modified Li-rich cathode material Li[Li0.26Ni0.07Co0.07Mn0.56]O2 for lithium ion battery

2014 ◽  
Vol 07 (06) ◽  
pp. 1440013 ◽  
Author(s):  
Xiangjun Li ◽  
Hongxing Xin ◽  
Xiaoying Qin ◽  
Xueqin Yuan ◽  
Di Li ◽  
...  
Keyword(s):  
Electrochemical Impedance ◽  
Rate Capability ◽  
Lithium Ion ◽  
Cycling Performance ◽  
Precipitation Method ◽  
Electrochemical Performances ◽  
Charge Transfer Reaction ◽  
Ion Diffusion ◽  
Co Precipitation ◽  
Kinetics Of

Lithium and Mn rich solid solution materials Li [ Li 0.26 Ni 0.07 Co 0.07 Mn 0.56] O 2 were synthesized by a carbonate co-precipitation method and modified with a layer of graphene. The graphene-modified cathodes exhibit improved rate capability and cycling performance as compared to the bare cathodes. Electrochemical impedance spectroscopy (EIS) analyses reveal that the improved electrochemical performances are due to acceleration kinetics of lithium-ion diffusion and the charge transfer reaction of the graphene-modified cathodes.

Improved performances of a LiNi0.6Co0.15Mn0.25O2 cathode material with full concentration-gradient for lithium ion batteries

RSC Advances ◽  
2016 ◽  
Vol 6 (105) ◽  
pp. 103747-103753 ◽  
Author(s):  
Zhonghui Sun ◽  
Dandan Wang ◽  
Yingying Fan ◽  
Liansheng Jiao ◽  
Fenghua Li ◽  
...  
Keyword(s):  
Cathode Material ◽  
Lithium Ion Batteries ◽  
Concentration Gradient ◽  
High Capacity ◽  
Lithium Ion ◽  
Precipitation Method ◽  
Co Precipitation

A novel high capacity cathode material with a full concentration-gradient (FCG) structure has been successfully synthesized by a modified hydroxide co-precipitation method.

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