MnCo2O4/g-C3N4 composite material preparation and its capacitance performance

2021 ◽  
Author(s):  
Qing Wang ◽  
Yirong Li ◽  
Haoran Gao ◽  
Jianfeng Dai ◽  
Weixue Li
Keyword(s):  
Composite Material ◽  
Electronic Transport ◽  
Retention Rate ◽  
Capacity Retention ◽  
Ion Migration ◽  
Discharge Rates ◽  
Excellent Electrochemical Performance ◽  
Capacitance Performance ◽  
Transport Channels ◽  
Material Preparation

MnCo2O4/g-C3N4 composite material was synthesized by the hydrothermal method, compared with MnCo2O4 without g-C3N4, it has excellent electrochemical performance. The composite material can reach a specific capacitance of 350 Fg[Formula: see text] at 1 Ag[Formula: see text]. The capacity retention rate is 96% after 1000 cycles at the rate of 2 Ag[Formula: see text]. Experiments show that g-C3N4 can effectively disperse and improve the conductivity of urchin-like MnCo2O4, and the composite of sufficient g-C3N4 can give full play to the performance of urchin-like MnCo2O4, provide faster electronic transport channels, effectively improve the ion migration rate, and make urchin-like MnCo2O4 increase the rate performance under high charge and discharge rates.

Preparation of LiCoO2 from Cathode Materials of Spent Lithium Ion Batteries

2011 ◽  
Vol 183-185 ◽  
pp. 1553-1557 ◽  
Author(s):  
Fang Gu ◽  
Qian Nie
Keyword(s):  
Lithium Ion Batteries ◽  
Discharge Capacity ◽  
Cathode Materials ◽  
Retention Rate ◽  
Ammonium Oxalate ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
Capacity Retention ◽  
Excellent Electrochemical Performance ◽  
Pure Phase

Preparation of LiCoO2 cathode materials from spent lithium ion batteries are presented. The processes contain reduction, separation, precipitation, regeneration. The optimum conditions of recovery are: the calcination temperature is 500°C, the volume rate of sulfuric acid and the water reaches 0.375, the hightest leach-ing rate of cobalt is 43.53%. According to the solubility of oxalate, ammonium oxalate is choiced as precipitation agent. The investigation of X-ray diffraction (XRD), scanning electron microscopy (SEM), charge-discharge testes at voltage ranges rate from 2.8V to 4.2V versus Li , 0.2 C rate are performed. The results reveal that the regenerative LiCoO2 is pure phase, initial discharge capacity is 128.63 mAh•g-1, after 50 cycles the discharge capacity is 118.61 mAh•g-1, capacity retention rate is 92.21%. The regenerative LiCoO2 exhibits excellent electrochemical performance and stability. The materials may find promising applications in lithium ion batteries.

scholarly journals Improving Retention Rate of LiNi0.8Co0.15Al0.05O2 Cathode Material Synthesized Using Glycerol Solvent

2020 ◽  
Vol 17 (3) ◽  
Author(s):  
Khaleel I. Hamad ◽  
Yangchuan Xing
Keyword(s):  
Cathode Material ◽  
Early Stage ◽  
Retention Rate ◽  
X Ray Diffraction ◽  
Capacity Retention ◽  
Sem Images ◽  
Li Ion ◽  
Material Preparation ◽  
Heat Released ◽  
Better Than

Abstract This paper reports an enhanced retention rate of LiNi0.8Co0.15Al0.05O2 (NCA) cathode material for Li-ion batteries synthesized with glycerol as a solvent and a reactant. Glycerol is a fuel and the heat released during synthesis could be considered as an additional free energy source for material preparation. Scanning electron microscopy (SEM) images and X-ray diffraction (XRD) results show an early stage of crystallization of the produced powder. Early crystallization in the NCA material at low temperatures was believed to hinder cationic mixing that would occur at higher temperatures during calcination. As a result, cycling of the NCA material shows a very stable capacity. The NCA material displays 97% capacity retention at 1C (1C = 200 mA/g) after 50 cycles, 87.6% at 0.3C after 100 cycles, and 93.6% at 0.1C after 70 cycles, which are better than those reported previously.

Electrochemical Performance Ni Doped Spinel LiMn2O4 Cathode for Lithium Ion Batteries

2011 ◽  
Vol 347-353 ◽  
pp. 290-300
Author(s):  
Yong Li Cui ◽  
Wen Jing Bao ◽  
Zheng Yuan ◽  
Quan Chao Zhuang ◽  
Zhi Sun
Keyword(s):  
Electrochemical Performance ◽  
Discharge Capacity ◽  
Retention Rate ◽  
Sol Gel ◽  
Lithium Ion ◽  
Cyclic Voltammogram ◽  
X Ray Diffraction ◽  
Capacity Retention ◽  
Excellent Electrochemical Performance ◽  
Charge Discharge

LiNixMn2-xO4 (x=0, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5) compounds with spinel crystal structure are synthesized by sol-gel method. The dependence of the physicochemical properties of these compounds has been extensively investigated by using X-ray diffraction (XRD), scanning electron microscope (SEM), cyclic voltammogram (CV) and charge-discharge test. It is found that as Mn is replaced by Ni, the initial capacity decreases, but the capacity retention is enhanced. Of all the LiNixMn2-xO4 (x=0, 0.05, 0.1, 0.2, 0.3, 0.4) compounds, the LiNi0.2Mn1.8O4 has best electrochemical performance, about 120mAhg-1 discharge capacity, its capacity retention rate of 96.6% after 100 cycles. However the LiNi0.5Mn1.5O4 sample shows excellent electrochemical performance at 4.7 V high potential, 150 mAhg-1 discharge capacity, above 110 mAhg-1 of capacity retention after 42 cycles of charge/discharge. The prepared LiNi0.5Mn1.5O4 powders sintered at 750 °C here has Fd3m space group.

Effect of Nitric Acid Modification on LiMn2O4 Prepared by Solution Combustion Synthesis

2011 ◽  
Vol 80-81 ◽  
pp. 332-336 ◽  
Author(s):  
Yan Xia ◽  
Mei Huang ◽  
Jun Ming Guo ◽  
Ying Jie Zhang
Keyword(s):  
Nitric Acid ◽  
Combustion Synthesis ◽  
Discharge Capacity ◽  
Retention Rate ◽  
Solution Combustion Synthesis ◽  
Manganese Acetate ◽  
Solution Combustion ◽  
Acid Modification ◽  
Capacity Retention ◽  
Liquid Combustion

Effect of nitric acid and the burning time on the liquid combustion synthesis of spinel LiMn2O4 has been studied, using lithium nitrite and Manganese acetate as raw a material. The results show that the main phases are all LiMn2O4, which can be obtained at 400-600 oC. Before modified, the impurity is Mn3O4 or Mn2O3. After modified, the impurity is only Mn3O4. The aggregation obviously reduced after adding nitric acid, it is indicated that the crystalline increased. With the increasing temperatures, the modified particle size was increased and the aggregation reduced. The initial discharge capacity and cycle stability improved at some extent too. Its first discharge capacity was 104.6, 112.8 and 117.7mAh/g synthesized at 400, 500, 600 oC, respectively, and the 30th capacity retention rate were 84.89%, 80.67% and 73.24%.

Influence of Oxygen Plasma Modification Carbon Fiber on Flexural Strength and Hydrothermal Properties of CF/PES Composite

2014 ◽  
Vol 926-930 ◽  
pp. 141-144
Author(s):  
Xu Cui ◽  
Yan Jiao Huang ◽  
Yu Gao ◽  
Shuo Wang
Keyword(s):  
Composite Material ◽  
Carbon Fiber ◽  
Flexural Strength ◽  
Plasma Treatment ◽  
Oxygen Plasma ◽  
Retention Rate ◽  
Test Method ◽  
Plasma Modification ◽  
Resin Matrix ◽  
Strength Retention

In this paper, low temperature oxygen plasma treatment method was adopted to process the carbon fiber surface. Flexural Strength test method was utilized to represent f composite material flexural strength. This paper observed flexural failure morphology of composite material by aid of SEM, then it compared the mechanical property, hygroscopicitiy and flexural strength retention rate of composite material before and after the plasma treatment. Results showed that the optimum treatment conditions of carbon fiber were 300W treatment power and 15-minute treatment time. Under the condition, the highest flexural strength value be increased by 19.55%.Saturated bibulous is low and bibulous rate is slow, flexural strength retention rate is 94.9%. And at the same time PES-C resin matrix can be strengthened, which will further improve the mechanical properties of composite materials.

scholarly journals Effects of pre-charge temperatures on gas production and electrochemical performances of lithium-ion batteries

2021 ◽  
Vol 248 ◽  
pp. 01040
Author(s):  
Shi Xiaoyan ◽  
Ma Leilei ◽  
Wang Jiantao
Keyword(s):  
Room Temperature ◽  
Influence Factor ◽  
Retention Rate ◽  
Lithium Ion ◽  
Gas Production ◽  
Electrochemical Performances ◽  
Capacity Retention ◽  
Film Forming ◽  
Charge Temperature

Pre-charge as a key step in the battery manufacture processes, which has a great impact on the film-forming properties and electrochemical performances, especially the Li-rich system batteries. As a key influence factor, it is necessary to clarify the effect of pre-charge temperature on battery performance. In this paper, we mainly studied the influence of different pre-charge temperatures (25°C, 40°C, 60°C) on the gas production and electrochemical performance of the batteries. The results show that the increase of the pre-charge temperature will result in the increase of gas production, and the gas components are mainly CO2, H2. After the long-term cycle, the sample under 40°C maintains the highest capacity retention rate, and as the pre-charge temperature increases, the median voltage of the battery can be effectively increased. In addition, compared with room temperature pre-charge, high pre-charge temperature samples have more excellent rate performance.

Facile Synthesis of Ni–Mn Layered Double Hydroxide Nanopetals on 3D Reduced Graphene Oxide/Ni Foam for High-Performance Supercapacitors

NANO ◽  
2020 ◽  
Vol 15 (02) ◽  
pp. 2050021
Author(s):  
Qi Tang ◽  
Menghan Ye ◽  
Li Ma ◽  
Tao Zhou ◽  
Mengyu Gan ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Layered Double Hydroxide ◽  
Electrode Material ◽  
Active Sites ◽  
Retention Rate ◽  
Ni Foam ◽  
Reduced Graphene ◽  
Capacitance Performance ◽  
Double Hydroxide

In this work, the Ni–Mn layered double hydroxide (Ni–Mn LDH) nanopetals are fabricated on three-dimensional reduced graphene oxide/Ni foam (RGO/NF) by one-step hydrothermal method, in which the suspension of graphene oxide (GO) is directly reduced by nickel foam (NF) to obtain NF/RGO. The composite, which consists of interconnected Ni–Mn LDH nanopetals, forms a macroporous structure. Such an open space can promote electrolyte dispersion and ion diffusion of active substances, thus enhancing capacitance performance. Remarkable, during crystal growth, RGO can not only provide active sites for Ni–Mn LDH nanopetals, but also effectively connect Ni–Mn LDH nanopetals to NF, further promoting the electrochemical behavior of composite material. Moreover, RGO possess reasonable chemical stability which can improve the mechanical properties of the composite to obtain good stability. The experimental results show that the NF/RGO electrode material with Ni–Mn LDH nanopetals has excellent specific capacitance of 2250[Formula: see text]F[Formula: see text]g[Formula: see text] at 1[Formula: see text]A[Formula: see text]g[Formula: see text], good rate performance (the capacitance retention rate is still 64.0% at 10[Formula: see text]A[Formula: see text]g[Formula: see text] and excellent cycle life (45.1% at 10[Formula: see text]A[Formula: see text]g[Formula: see text] after 5000 cycles). NR/NM–LDH is used as the positive electrode and activated carbon is used as the negative electrode to assemble the asymmetric supercapacitor, the proper power density and energy density indicates that the NR/NM–LDH composite has great potential as an electrode material for supercapacitors.

scholarly journals Serial Disulfide Polymers as Cathode Materials in Lithium-Sulfur Battery: Materials Optimization and Electrochemical Characterization

2020 ◽  
Vol 10 (7) ◽  
pp. 2538
Author(s):  
Jing Wang ◽  
Shichao Zhang
Keyword(s):  
Carbon Black ◽  
Cathode Materials ◽  
Retention Rate ◽  
Specific Capacity ◽  
Peanut Oil ◽  
Electrochemical Performances ◽  
Capacity Retention ◽  
Tung Oil ◽  
Conductive Carbon Black ◽  
Copolymer Poly

Herein, a series of novel disulfide polymers were synthesized by using the raw materials of diallyl-o-phthalate, tung oil, peanut oil, and styrene. Four kinds of products: Poly (sulfur-diallyl-o-phthalate) copolymer, poly (sulfur-tung oil) copolymer, poly (sulfur-peanut oil) copolymer, and poly (sulfur-styrene-peanut oil) terpolymer were characterized, and their solubility was studied and compared. Among the four kinds of disulfide polymers, poly (sulfur-styrene-peanut oil) terpolymer had the best solubility in an organic solvent, and it was chosen to be the active cathode material in Li-S battery. Subsequently, two different conductive additives—conductive carbon black and graphene were separately blended with this terpolymer to prepare two battery systems. The electrochemical performances of the two batteries were compared and analyzed. The result showed that the initial specific capacity of poly (sulfur-styrene-peanut oil) terpolymer (blended with conductive carbon black) battery was 935.88 mAh/g, with the capacity retention rate about 43.5%. Comparingly, the initial specific capacity of poly (sulfur-styrene-peanut oil) terpolymer (blended with graphene) battery was 1008.35 mAh/g, with the capacity retention rate around 60.59%. Therefore, the battery system of poly (sulfur-styrene-peanut oil) terpolymer with graphene showed a more stable cycle performance and better rate performance. This optimized system had a simple and environmental-friendly synthesis procedure, which showed a great application value in constructing cathode materials for the Li-S battery.

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