High-Rate and Long-Life Cycle of Nano-LiMn2O4 Under High Cut-Off Potential

2020 ◽  
pp. 1-18
Author(s):  
Zulhadi Radzi ◽  
B Vengadaesvaran ◽  
Nasrudin Abd Rahim ◽  
Adarsh Kumar Pandey ◽  
Khairul Helmy Arifin ◽  
...  
Keyword(s):  
Lattice Strain ◽  
Organic Reagent ◽  
High Rate ◽  
Electrochemical Performances ◽  
Hydrothermal Route ◽  
Capacity Retention ◽  
Nanostructured Particles ◽  
Pure Phase ◽  
Small Lattice ◽  
Spinel Structures

Abstract Nano-LiMn2O4 was successfully synthesized by a low-temperature hydrothermal route with the absence of post-calcination treatment. Employing ethanol as an organic reagent triggers the formation of nanostructured particles approximately 30.39 nm in diameter, associated with 0.7 % lattice strain. The pure phase of nano-LiMn2O4/Li displays outstanding electrochemical performances. Under 4.6 V vs Li+/Li cut-off potential, 74.3 % of capacity is reserved when C-rate is increased by 50 times, while excellent capacity restoration of 96.9 % after cycled again at 1 C. After 331 cycles, capacity retention of 84.3 % is harvested by nano-LiMn2O4/Li, implying the absence of phase transformations in spinel structures under such abuse condition. This remarkable structural stability can be attributed to the small lattice strain, associated with high Li+ diffusion coefficient, which is estimated to be 10-9.76 cm2 s-1 by the EIS technique. Additionally, Li+ extraction is more favourable when nano-LiMn2O4/Li is charged up to 4.6 V vs Li+/Li, interpreted by the polarization resistance (Rp) of the cell.

scholarly journals In-Situ Annealed Ti3C2Tx MXene Based All-Solid-State Flexible Zn-Ion Hybrid Micro Supercapacitor Array with Enhanced Stability

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
La Li ◽  
Weijia Liu ◽  
Kai Jiang ◽  
Di Chen ◽  
Fengyu Qu ◽  
...  
Keyword(s):  
High Energy ◽  
High Rate ◽  
High Energy Density ◽  
Electrochemical Performances ◽  
Integrated Electronics ◽  
Long Term Stability ◽  
Hybrid Supercapacitors ◽  
Portable Electronics

AbstractZn-ion hybrid supercapacitors (SCs) are considered as promising energy storage owing to their high energy density compared to traditional SCs. How to realize the miniaturization, patterning, and flexibility of the Zn-ion SCs without affecting the electrochemical performances has special meanings for expanding their applications in wearable integrated electronics. Ti3C2Tx cathode with outstanding conductivity, unique lamellar structure and good mechanical flexibility has been demonstrated tremendous potential in the design of Zn-ion SCs, but achieving long cycling stability and high rate stability is still big challenges. Here, we proposed a facile laser writing approach to fabricate patterned Ti3C2Tx-based Zn-ion micro-supercapacitors (MSCs), followed by the in-situ anneal treatment of the assembled MSCs to improve the long-term stability, which exhibits 80% of the capacitance retention even after 50,000 charge/discharge cycles and superior rate stability. The influence of the cathode thickness on the electrochemical performance of the MSCs is also studied. When the thickness reaches 0.851 µm the maximum areal capacitance of 72.02 mF cm−2 at scan rate of 10 mV s−1, which is 1.77 times higher than that with a thickness of 0.329 µm (35.6 mF cm−2). Moreover, the fabricated Ti3C2Tx based Zn-ion MSCs have excellent flexibility, a digital timer can be driven by the single device even under bending state, a flexible LED displayer of “TiC” logo also can be easily lighted by the MSC arrays under twisting, crimping, and winding conditions, demonstrating the scalable fabrication and application of the fabricated MSCs in portable electronics.

scholarly journals High Capacity and Fast Kinetics of Potassium-Ion Batteries Boosted by Nitrogen-Doped Mesoporous Carbon Spheres

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Jiefeng Zheng ◽  
Yuanji Wu ◽  
Yong Tong ◽  
Xi Liu ◽  
Yingjuan Sun ◽  
...  
Keyword(s):  
Mesoporous Carbon ◽  
Active Sites ◽  
Carbon Materials ◽  
Potassium Ion ◽  
High Rate ◽  
Electrochemical Performances ◽  
Carbon Spheres ◽  
Fast Kinetics ◽  
Nitrogen Doped ◽  
Economic Price

AbstractIn view of rich potassium resources and their working potential, potassium-ion batteries (PIBs) are deemed as next generation rechargeable batteries. Owing to carbon materials with the preponderance of durability and economic price, they are widely employed in PIBs anode materials. Currently, porosity design and heteroatom doping as efficacious improvement strategies have been applied to the structural design of carbon materials to improve their electrochemical performances. Herein, nitrogen-doped mesoporous carbon spheres (MCS) are synthesized by a facile hard template method. The MCS demonstrate larger interlayer spacing in a short range, high specific surface area, abundant mesoporous structures and active sites, enhancing K-ion migration and diffusion. Furthermore, we screen out the pyrolysis temperature of 900 °C and the pore diameter of 7 nm as optimized conditions for MCS to improve performances. In detail, the optimized MCS-7-900 electrode achieves high rate capacity (107.9 mAh g−1 at 5000 mA g−1) and stably brings about 3600 cycles at 1000 mA g−1. According to electrochemical kinetic analysis, the capacitive-controlled effects play dominant roles in total storage mechanism. Additionally, the full-cell equipped MCS-7-900 as anode is successfully constructed to evaluate the practicality of MCS.

Enhanced Electrochemical Hydrogen Storage Characteristics of the as-Spun Mg2Ni-Type Alloys by Substituting Ni with M (M=Cu, Co)

2012 ◽  
Vol 457-458 ◽  
pp. 572-577
Author(s):  
Yang Huan Zhang ◽  
Bao Wei Li ◽  
Hui Ping Ren ◽  
Zai Guang Pang ◽  
Zhong Hui Hou ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Melt Spinning ◽  
Nanocrystalline Structure ◽  
Amorphous Structure ◽  
High Rate ◽  
Electrochemical Performances ◽  
Secondary Phases ◽  
Nanocrystalline And Amorphous ◽  
Electrochemical Hydrogen Storage ◽  
Rate Discharge

Mg2Ni-type Mg20Ni10-xMx (M=Cu, Co; x=0, 1, 2, 3, 4) electrode alloys with nanocrystalline and amorphous structure were synthesized by melt-spinning technique. The microstructures of the as-spun alloys were characterized by XRD, SEM and HRTEM. The electrochemical hydrogen storage properties of the experimental alloys were measured. The obtained results show that the as-spun (M=Cu) alloys hold an entire nanocrystalline structure, whereas the as-spun (M=Co) alloys display a nanocrystalline and amorphous structure, confirming that the substitution of Co for Ni facilitates the glass formation in the Mg2Ni-type alloy. Furthermore, such substitution results in the formation of secondary phases Mg2Cu and MgCo2 instead of changing the major phase of Mg2Ni. The substitution of M (M=Cu, Co) for Ni markedly improves the electrochemical performances of the alloys, involving the discharge capacity and the cycle stability as well as the high rate discharge ability.

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.

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.

Hybrid ZnCo2O4@Co3S4 Nanowires for High-Performance Asymmetric Supercapacitors

2020 ◽  
Vol 15 (12) ◽  
pp. 1552-1558
Author(s):  
Yongli Tong ◽  
Xinyu Cheng ◽  
Dongli Qi ◽  
Baoqian Chi ◽  
Weiqiang Zhang
Keyword(s):  
High Performance ◽  
Reaction Path ◽  
Nickel Foam ◽  
Energy Storage Materials ◽  
Electrochemical Performances ◽  
Hydrothermal Route ◽  
Asymmetric Supercapacitors ◽  
High Area ◽  
Facile Hydrothermal Route

We successfully fabricate hierarchical ZnCo2O4@Co3S4 nanowires directly supported on nickel foam by a facile hydrothermal route. The as-synthesized product possesses large specific surface area and short reaction path, which result in superior electrochemical performances as the electrode of supercapacitor (SC). The obtained electrode material shows high area capacitance of 2.02 C g-1 at current density of 0.8 A g-1 with 95.3% retention of initial capacitance after 6000 cycles. Moreover, the assembled asymmetric supercapacitor (ASC) device using ZnCo2O4@Co3S4 nanowires as anode material displays noticeable electrochemical capability with an energy density of 79.8 mW h g-1 at power density of 1795 W kg-1 and 73.2 mW h g-1 at 9760 W kg-1. In addition, the device shows remarkable cycling capability, maintaining 82.2% retention after long-term cycles. It reveals the as-fabricated material would be promising energy storage materials.

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.

Modification of Li- and Mn-Rich Cathode Materials via Formation of the Rock-Salt and Spinel Surface Layers for Steady and High-Rate Electrochemical Performances

2020 ◽  
Vol 12 (29) ◽  
pp. 32698-32711
Author(s):  
Sandipan Maiti ◽  
Hadar Sclar ◽  
Rosy ◽  
Judith Grinblat ◽  
Michael Talianker ◽  
...  
Keyword(s):  
Rock Salt ◽  
Cathode Materials ◽  
High Rate ◽  
Electrochemical Performances ◽  
Surface Layers
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