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

Research on Low Temperature Performance of the F-doped LiFePO4/C Cathode Materials

2011 ◽  
Vol 14 (3) ◽  
pp. 147-152 ◽  
Author(s):  
Borong Wu ◽  
Ying Zhang ◽  
Ning Li ◽  
Chunwei Yang ◽  
Zhaojun Yang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Cathode Materials ◽  
High Rate ◽  
Degree Of Polarization ◽  
Electrochemical Performances ◽  
Sem Images ◽  
Intrinsic Conductivity ◽  
Undoped Material ◽  
Structure Changes ◽  
Better Than

F-doped LiFePO4/C cathode materials were synthesized by two-step solid-state reaction route. The F-doped LiFePO4/C increases the intrinsic conductivity, the diffusion of lithium ions, also improves the high-rate and low-temperature performances of LiFePO4. The SEM images reveal some small morphology changes of the two kinds of the materials, so the improved properties may not due to grain size changes but crystal structure changes. The F-doped material has a higher capability at low temperature. At -20°C, with the rate of 0.5C, the discharge capacity was 82mAhg-1, higher than that of undoped material(65mAhg-1) and the result is better than the previous study[17](65mAhg-1 at the rate of 0.3C), and the disparity would enlarge with the rate increased. The CV plots indicate that the doped material reveals less degree of polarization. F-doping sample improves the electrical conductivity of material, accelerating the process of Li+ deintercalation, therefore, improving the electrochemical performances at low temperature.

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.

Effect of ion doping on the electrochemical performances of LiFePO4–Li3V2(PO4)3 composite cathode materials

RSC Advances ◽  
2014 ◽  
Vol 4 (30) ◽  
pp. 15332-15339 ◽  
Author(s):  
Chao Jin ◽  
Xudong Zhang ◽  
Wen He ◽  
Yan Wang ◽  
Haiming Li ◽  
...  
Keyword(s):  
Cathode Materials ◽  
Composite Cathode ◽  
Electrochemical Performances ◽  
Ion Doping

This review highlights the effect of ion doping on the electrochemical performances of LiFePO4–Li3V2(PO4)3 composite cathode materials.

Surfactant-assisted synthesis of LiMn2O4 particles as high-rate and long-life cathode materials for lithium-ion batteries

Ionics ◽  
2017 ◽  
Vol 24 (6) ◽  
pp. 1553-1560
Author(s):  
Sheng Chen ◽  
Xiaoning Xu ◽  
Xiaoyu Liu ◽  
Yanming Wang ◽  
Fei Wang
Keyword(s):  
Lithium Ion Batteries ◽  
Cathode Materials ◽  
Lithium Ion ◽  
High Rate ◽  
Long Life ◽  
Surfactant Assisted
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