Improved structural and electrochemical performances of LiNi0.5Mn1.5O4 cathode materials by Cr3+ and/or Ti4+ doping

RSC Advances ◽  
2015 ◽  
Vol 5 (121) ◽  
pp. 99856-99865 ◽  
Author(s):  
Li Wang ◽  
Dan Chen ◽  
Jiangfeng Wang ◽  
Guijuan Liu ◽  
Wei Wu ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Electrochemical Performance ◽  
Cathode Materials ◽  
Rate Capability ◽  
Cycling Stability ◽  
Electrochemical Performances ◽  
Ion Diffusion ◽  
Ti Doping ◽  
Co Doped

The Cr and/or Ti doping leads to the enhanced rate capability and cycling stability. The co-doped sample exhibits the optimal electrochemical performance due to the presence of appropriate Mn3+ content and higher Li+ ion diffusion coefficient.

Enhanced Electrochemical Performances of Ni-Rich LiNi0.8Co0.15Al0.05O2 Cathode Materials by Ti Doping or/and Al(OH)3 Coating

2020 ◽  
Vol 12 (9) ◽  
pp. 1283-1288 ◽  
Author(s):  
Un-Gi Han ◽  
Yeon-Ju Lee ◽  
Gyu-Bong Cho ◽  
Su-Gun Lim ◽  
Ki-Won Kim ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Field Emission ◽  
Cathode Materials ◽  
Electrochemical Techniques ◽  
Cycling Stability ◽  
Side Reactions ◽  
Electrochemical Performances ◽  
Layer Spacing ◽  
X Ray ◽  
Ti Doping

To improve the electrochemical properties of Ni-rich LiNi0.8Co0.15Al0.05O2 (LiNCA) cathode material, Ti doped or/and Al(OH)3 coated were by co-precipitation-assisted solid-phase and ball milling method was employed in this work. The morphology, structure, and electrochemical performance of the cathode materials were evaluated by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) with energy dispersive X-ray spectrometer (EDS), field emission transmission electron microscopy (FETEM) and electrochemical techniques. Ti doping is introduced into the octahedral lattice space occupied by Li-ions to widen the Li layer spacing and thereby increase the lithium diffusion kinetics. The Al(OH)3 coating also formed a non-uniform layer on the outside of LiNCA, thereby inhibiting side reactions between the electrode and the electrolyte. As a result, the LiNCA electrode showed a high initial discharge capacity of 167.4 mAh/g. However, after 100 cycles, it showed poor cycling stability of 41.7%. In contrast, Ti doped and Al(OH)3 coated LiNCA showed the best cycling stability of 82.2% after 100 cycles.

Effects of Na and V Co-Doping on Electrochemical Performance of LiFePO4/C

2013 ◽  
Vol 724-725 ◽  
pp. 1067-1070
Author(s):  
Ning Yu Gu ◽  
Yang Li ◽  
Chao Li
Keyword(s):  
Solid State ◽  
Electrochemical Performance ◽  
Lithium Ion Batteries ◽  
Cathode Materials ◽  
Lithium Ion ◽  
Electrochemical Performances ◽  
Solid State Method ◽  
Co Doping ◽  
State Method ◽  
Co Doped

To enhance the electrochemical performance of LiFePO4/C, Na and V have been co-doped in cathode material of the lithium ion batteries. A series of Na and V doped samples Li0.97Na0.03Fe(1-x)VxPO4/C (x=0, 0.01, 0.03, 0.05) cathode materials are synthesized by solid state method. Results show that the Li0.97Na0.03Fe0.97V0.03PO4/C exhibited the best electrochemical performances.

Tris(trimethylsilyl) phosphite (TMSPi) as an electrolyte additive for LiNi0.5Co0.2Mn0.3O2 cathode materials at elevated voltage and temperature

2021 ◽  
Author(s):  
Xiao Yu ◽  
Zhiyong Yu ◽  
Jishen Hao ◽  
Hanxing Liu
Keyword(s):  
Discharge Capacity ◽  
Cathode Materials ◽  
Solid Electrolyte Interphase ◽  
Rate Capability ◽  
Electrochemical Performances ◽  
Initial Discharge Capacity ◽  
Capacity Retention ◽  
Electrolyte Additive ◽  
Interface Impedance ◽  
Initial Discharge

Electrolyte additive tris(trimethylsilyl) phosphite (TMSPi) was used to promote the electrochemical performances of LiNi[Formula: see text]Co[Formula: see text]Mn[Formula: see text]O2 (NCM523) at elevated voltage (4.5 V) and temperature (55[Formula: see text]C). The NCM523 in 2.0 wt.% TMSPi-added electrolyte exhibited a much higher capacity (166.8 mAh/g) than that in the baseline electrolyte (118.3 mAh/g) after 100 cycles under 4.5 V at 30[Formula: see text]C. Simultaneously, the NCM523 with 2.0 wt.% TMSPi showed superior rate capability compared to that without TMSPi. Besides, after 100 cycles at 55[Formula: see text]C under 4.5 V, the discharge capacity retention reached 87.4% for the cell with 2.0 wt.% TMSPi, however, only 24.4% of initial discharge capacity was left for the cell with the baseline electrolyte. A series of analyses (TEM, XPS and EIS) confirmed that TMSPi-derived solid electrolyte interphase (SEI) stabilized the electrode/electrolyte interface and hindered the increase of interface impedance, resulting in obviously enhanced electrochemical performances of NCM523 cathode materials under elevated voltage and/or temperature.

N-doped porous carbon derived from walnut shells with enhanced electrochemical performance for supercapacitor

2019 ◽  
Vol 12 (03) ◽  
pp. 1950042 ◽  
Author(s):  
Yunfeng Wang ◽  
Honghui Jiang ◽  
Shewen Ye ◽  
Jiaming Zhou ◽  
Jiahao Chen ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Specific Capacitance ◽  
Porous Carbon ◽  
Low Cost ◽  
High Specific Capacitance ◽  
Cycling Stability ◽  
Electrochemical Performances ◽  
Walnut Shells ◽  
Electrochemical Cycling ◽  
Elemental Doping

As the low-cost, natural multi-component for elemental doping and environment-friendly characteristics, biomass-derived porous carbon for energy storage attracts intense attention. Herein, walnut shells-based porous carbon has been obtained through carbonization, hydrothermal and activation treatment. The corresponding porous carbon owns superior electrochemical performances with specific capacitance reaching up to 462[Formula: see text]F[Formula: see text]g[Formula: see text] at 1[Formula: see text]A[Formula: see text]g[Formula: see text], and shows excellent cycling stability (5000 cycles, [Formula: see text]94.2% of capacitance retention at 10[Formula: see text]A[Formula: see text]g[Formula: see text]). Moreover, the symmetry supercapacitor achieves high specific capacitance (197[Formula: see text]F[Formula: see text]g[Formula: see text] at 1[Formula: see text]A[Formula: see text]g[Formula: see text]), relevant electrochemical cycling stability (5000 cycles, 89.2% of capacitance retention at 5[Formula: see text]A[Formula: see text]g[Formula: see text]) and high power/energy density (42.8[Formula: see text]W[Formula: see text]h[Formula: see text]kg[Formula: see text] at 1249[Formula: see text]W[Formula: see text]kg[Formula: see text]). Therefore, the facile synthesis approach and superb electrochemical performance ensure that the walnut shells-derived porous carbon is a promising electrode material candidate for supercapacitors.

Facile synthesis of three-dimensional flower-like MoO2–graphene nanostructures with enhanced electrochemical performance

2016 ◽  
Vol 4 (27) ◽  
pp. 10414-10418 ◽  
Author(s):  
Ying Ma ◽  
Yulong Jia ◽  
Lina Wang ◽  
Min Yang ◽  
Yingpu Bi ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Specific Capacitance ◽  
Hydrothermal Reaction ◽  
Three Dimensional ◽  
Rate Capability ◽  
Cycling Stability ◽  
Facile Synthesis ◽  
Enhanced Electrochemical Performance ◽  
Good Rate Capability ◽  
Graphene Nanostructures

Three-dimensional MoO2–G flower-like nanostructures were synthesized through a facile hydrothermal reaction and showed significantly improved specific capacitance, good rate capability and cycling stability.

Synthesis of LiFePO4/C Composite Cathode Materials by Solid State Method Using Mixed Iron Sources

2013 ◽  
Vol 734-737 ◽  
pp. 2541-2544
Author(s):  
Wei Wang ◽  
Zheng Zhang ◽  
Dao Wushuang Shi ◽  
Xing Quan Liu
Keyword(s):  
Solid State ◽  
Electrochemical Performance ◽  
Cathode Materials ◽  
Lithium Ion ◽  
Composite Cathode ◽  
Molar Ratio ◽  
Electrochemical Performances ◽  
Solid State Method ◽  
State Reduction ◽  
Solid State Reduction

The olivine LiFePO4/C composite cathode materials for lithium-ion batteries were synthesized by solid state reduction method using mixed iron sources. The effects of different temperatures on the electrochemical performance of as-synthesized cathode materials were investigated and analyzed. The crystal structures and the electrochemical performances were characterized by SEM, galvanostatical charge-discharge testing and AC-impedance, respectively. The results demonstrated that the LiFePO4/C composite cathode material synthesized at 710°C and with 1/2(FeC2O4·2H2O/Fe2O3) molar ratio of mixed iron sources has the better electrochemical performance, it has a discharge capacity of 126.1mAh/g at 0.2C and the capacity is kept at 113.8mAh/g after 20 cycles.

Novel Cathode Electrode with Superior Rate Capability Using Perforated Aluminum Current Collector for Lithium-Ion Batteries

2020 ◽  
Vol 12 (10) ◽  
pp. 1465-1468
Author(s):  
Jin-Ju Bae ◽  
Ji-Woong Shin ◽  
Seong-Jae Kim ◽  
Tae-Whan Hong
Keyword(s):  
Electrochemical Performance ◽  
Lithium Ion Batteries ◽  
Cathode Materials ◽  
Performance Indicators ◽  
Rate Capability ◽  
Lithium Ion ◽  
Current Collector ◽  
Aluminum Foil ◽  
Cathode Electrode ◽  
The Relationship

Electrodes were fabricated using a perforated aluminum current collector and a standard aluminum foil, and the relationship between the electrochemical performance of the battery and the current collector was investigated. The perforated aluminum foil improved the contact characteristics between the cathode materials particles and the current collector. Also, electrochemical performance indicators such discharge capacity and rate characteristics were improved due to the increased adhesion of the electrode using the perforated current collector.

scholarly journals Self-Substitution and the Temperature Effects on the Electrochemical Performance in the High Voltage Cathode System LiMn1.5+xNi0.5−xO4 (x = 0.1)

2017 ◽  
Vol 14 (2) ◽  
Author(s):  
Yun Xu ◽  
Mingyang Zhao ◽  
Syed Khalid ◽  
Hongmei Luo ◽  
Kyle S. Brinkman
Keyword(s):  
Electrochemical Performance ◽  
High Voltage ◽  
Cathode Materials ◽  
Metal Ion ◽  
Structural Changes ◽  
Rate Capability ◽  
Performance Testing ◽  
Capacity Loss ◽  
Stable Performance ◽  
Li Ion

The high voltage cathode material, LiMn1.6Ni0.4O4, was prepared by a polymer-assisted method. The novelty of this work is the substitution of Ni with Mn, which already exists in the crystal structure instead of other isovalent metal ion dopants which would result in capacity loss. The electrochemical performance testing including stability and rate capability was evaluated. The temperature was found to impose a change on the valence and structure of the cathode materials. Specifically, manganese tends to be reduced at a high temperature of 800 °C and leads to structural changes. The manganese substituted LiMn1.5Ni0.5O4 (LMN) has proved to be a good candidate material for Li-ion battery cathodes displaying good rate capability and capacity retention. The cathode materials processed at 550 °C showed a stable performance with negligible capacity loss for 400 cycles.

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.

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