scholarly journals Effect of precursor particle size and morphology on lithiation of Ni0.6Mn0.2Co0.2(OH)2

Author(s):  
Marianna Hietaniemi ◽  
Tao Hu ◽  
Juho Välikangas ◽  
Janne Niittykoski ◽  
Ulla Lassi

AbstractIn this paper, Ni0.6Mn0.2Co0.2(OH)2 precursors with several different morphologies and particle sizes are mixed with Li2CO3 and heat treated for 5, 7.5 and 10 h. The effects of the precursor properties on the degree of lithiation, electrochemical properties and volumetric capacities of lithiated product are compared. Based on the characterization results, a small (3 μm), narrow span precursor can be lithiated in a short period of time (5 h) and has good initial discharge capacity (185 mA h g− 1) and capacity retention (93% for 55 cycles). In contrast, a large wide-span precursor requires over 10 h for full lithiation. A highly porous precursor can be lithiated faster than traditional large wide-span materials, and has low cation mixing and good crystallinity. However, the volumetric energy density of porous material is low after lithiation compared to the other tested materials. Capacity retention after washing correlated with crystallographic properties of the sample. Graphic abstract

2006 ◽  
Vol 510-511 ◽  
pp. 1102-1105
Author(s):  
Seon Hye Kim ◽  
Kwang Bo Shim ◽  
Kyoung Ran Han ◽  
Chang Sam Kim

Li(Ni1/3Co1/3Mn1/3)O2 powders were synthesized by using an ultrasonic spray pyrolysis method, and then heat-treated at 900 or 1000°C for 20 h. The morphology of the as-synthesized powder was spherical. The post heat-treatment changed the particle size and morphology of the synthesized powders. Structural characteristics of the heat-treated powders were analyzed using XRD and SEM, and their electrochemical properties were compared. Higher first discharge capacity was obtained from the powder heat-treated at 1000°C, but its rough and rugged surface might cause a rapid decrease of the capacity retention.


2017 ◽  
Vol 4 (11) ◽  
pp. 1806-1812 ◽  
Author(s):  
Shibing Zheng ◽  
Jinyan Hu ◽  
Weiwei Huang

A novel high-capacity cathode material C4Q/CMK-3 for SIBs shows an initial discharge capacity of 438 mA h g−1 and a capacity retention of 219.2 mA h g−1 after 50 cycles.


Author(s):  
Xiao Yu ◽  
Zhiyong Yu ◽  
Jishen Hao ◽  
Hanxing Liu

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.


2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Bao Zhang ◽  
Tao Zeng ◽  
Jiafeng Zhang ◽  
Chunli Peng ◽  
Junchao Zheng ◽  
...  

Nanosized spherical LiFePO4/C composite was synthesized from nanosized spherical FePO4·2H2O, Li2C2O4, aluminum oxide, titanium oxide, oxalic acid, and sucrose by binary sintering process. The phases and morphologies of LiFePO4/C were characterized using SEM, TEM, CV, EIS, EDS, and EDX as well as charging and discharging measurements. The results showed that the as-prepared LiFePO4/C composite with good conductive webs from nanosized spherical FePO4·2H2O exhibits excellent electrochemical performances, delivering an initial discharge capacity of 161.7 mAh·g−1at a 0.1 C rate, 152.4 mAh·g−1at a 1 C rate and 131.7 mAh·g−1at a 5 C rate, and the capacity retention of 99.1%, 98.7%, and 95.8%, respectively, after 50 cycles. Meanwhile, the high and low temperature performance is excellent for 18650 battery, maintaining capacity retention of 101.7%, 95.0%, 88.3%, and 79.3% at 55°C, 0°C, −10°C, and −20°C by comparison withthat of room temperature (25°C) at the 0.5 C rate over a voltage range of 2.2 V to 3.6 V, respectively.


2012 ◽  
Vol 581-582 ◽  
pp. 570-573
Author(s):  
Jia Feng Zhang ◽  
Bao Zhang ◽  
Xue Yi Guo ◽  
Jian Long Wang ◽  
He Zhang Chen ◽  
...  

The LiFe0.98Ni0.01Nb0.01PO4/C was synthesized by carbon reduction route using FePO4•2H2O as precursor. The LiFe0.98Ni0.01Nb0.01PO4/C sample was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and electrochemical measurements. The XRD analysis, SEM and TEM images show that sample has the good crystal structure, morphology and carbon coating. The charge-discharge tests demonstrate that the powder has the better electrochemical properties, with an initial discharge capacity of 164.6 mAh•g−1 at current density of 0.1 C. The capacity retention reaches 99.8% after 100 cycles at 0.1C.


2015 ◽  
Vol 3 (15) ◽  
pp. 7870-7876 ◽  
Author(s):  
Xiaoqin Zhao ◽  
Min Liu ◽  
Yong Chen ◽  
Bo Hou ◽  
Na Zhang ◽  
...  

L-Ti3C2 was prepared by exfoliating Ti3AlC2 in 40% HF. With sulfur-loaded L-Ti3C2 as cathodes, Li–S batteries deliver a high initial discharge capacity of 1291 mA h g−1, an excellent capacity retention of 970 mA h g−1 and coulombic efficiency of 99% after 100 cycles.


2013 ◽  
Vol 575-576 ◽  
pp. 7-10
Author(s):  
Chun Xia Gong ◽  
Oluwatosin Emmanued Bankole ◽  
Li Xu Lei

Li0.96Na0.04Ni1/3Co1/3Mn1/3O2with PEG400 or PEG2000 as additive was synthesized by coprecipitation method. Xray diffraction pattern reveals that both the products with PEG400 and PEG2000 are pure phase. Scanning Electron Microscopy shows that the average sizes of the powders are 100 nm and 80 nm, respectively. The sample with PEG 2000 has initial discharge capacity (205.8 Mah×g1) and the sample with PEG 400 exhibits good cycle performance with the capacity retention of 86.34 % after 90 cycles compared to that has no additive (167.6 mAh.g-1and 71.18 %) in the cut-off voltage of 2.0-4.5 V at 0.1 C rate. Therefore, PEG400 or PEG2000 as additive should improve the performance of Li0.96Na0.04Ni1/3Co1/3Mn1/3O2cathode material.


2013 ◽  
Vol 726-731 ◽  
pp. 2940-2944 ◽  
Author(s):  
Feng Pei ◽  
Yue Wu ◽  
Wen Hua Zhang ◽  
Xu Tian ◽  
Ji Yu

LiFePO4 was prepared using recovered materials from waste Li-ion battery. The recovered materials after treatment was mixed with Li2CO3, Fe (NO3) 3·9H2O and NH4H2PO4 to adjust the Li/Fe/P molar ratio equal to 1.05/1/1. The raw material was mixed with super-p and calcined in muffle to get LiFePO4 by a solid-state reaction. Optimal conditions were: 700°C, N2 ambience, 10h, and Fe/C=1/1.5 (mol). The characterization results showed that the product was irregular particles with size 5-10μm and good dispersion. When discharged in the range of 2.2~4.2V, the initial discharge capacity was 141.4mAh/g at 0.1C, 103.1mAh/g at 1C. The capacity retention was 97.2% after 300 cycles at 1C showing satisfactory stability.


2019 ◽  
Author(s):  
◽  
Khaleel Idan Hamad

Many synthesis techniques like sol-gel, co-precipitation, hydrothermal, pyrolysis, and many more have been used to synthesize batteries' active electrode materials. High surface area cathode materials with smaller nanoparticles are favored for their higher reactivity compared to materials with particles of larger size. Sol-gel and co-precipitation methods have been primarily adopted because they can produce the desirable particle size easily and on a large scale. This dissertation details an efficient and cost-effective process for using a newly developed sol-gel method that uses glycerol solvent instead of the conventionally used water. Glycerol has three hydroxyl groups (OH) instead of one in water. These can play an important role in nanoparticle formation at earlier stages by speeding up the reaction. One of the main reasons for capacity fade in batteries is cationic mixing between Ni2+ and Li+. This results in blocking of the Li+ path and ultimately poor cyclability. This capacity fade has been successfully minimized in our current work by taking advantage of the high heat released from glycerol to get partially crystalline nanoparticles that could mitigate cationic mixing at high temperatures. The first cathode material synthesized using glycerol solvent was LiMn1/3Ni1/3Co1/3O2 (LMNC) layered oxide cathode material. Temperature's effects on the particles' morphologies, sizes, and electrochemical performances have been studied at four different temperatures. LMN2 was annealed at 900 �C/8hr and shows desirable particles size of ~ 0.3 (�_m), an initial discharge capacity of 177.1 mAh/g in the first cycle, and a superior capacity retention of 83.7% after 100 cycles. The process takes eight hours, rather than >12hr when using other solvents to prepare LMNC material at high temperatures. The results also demonstrate the higher stability and lower cationic mixing after 100 cycles. To increase capacity and voltage, lithium-rich cathode materials with the formula Li1.2Mn0.51Ni0.145+xCo0.145-xO2 (x = 0 (LR2), 0.0725 (LR1)) have been successfully synthesized. In this material, cobalt (Co) content has been decreased by half and the larger produced particles have suppressed the total activation of Li2MnO3 phase in the first charge cycle. The specific discharge capacity retention of LR1 at 1C between 2 and 4.8 V was more than 100% after 100 cycles. Further improvements to LR1 cathode materials have led to an increase in the initial discharge capacity to 248 mAh/g at 0.1C. This is achieved by using an equimolecular combination of acetate and nitrate salt anions (LRACNI) with cornstarch. Cornstarch acts as a capping agent with the nitrate salt anions, and a gelling agent with acetate based anions. LRACNI shows an intermediate particle size with satisfactory capacity retention upon cycling and the lowest cationic mixing. LiNi0.8Co0.15Al0.05O2 (NCA) is one of the most commercialized cathode materials for lithium-ion batteries. It is challenging to have a high Ni content with Li in one combination electrode because cationic mixing increases proportionally. The use of glycerol has diminished the cationic mixing. High capacity retentions of 97% at 1C after 50 cycles, 87.6% at 0.3C after 100 cycles, and 93.6% at 0.1C after 70 cycles have been successfully achieved, which are better than those previously reported.


2013 ◽  
Vol 291-294 ◽  
pp. 771-777
Author(s):  
Hua Li Zhu ◽  
Ming Xu ◽  
Zhao Yong Chen

Spinel LiMn2O4 was prepared by solid state reaction from composite carbonate precursors Li2CO3 and MnCO3, which were obtained by coprecipitation method. The physicochemical properties of spinel LiMn2O4and its precursor were investigated by simultaneous thermogravimetry-differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD), scanning electron micrographs (SEM) and galvanostatic charge-discharge test, respectively. The carbonate precursors demonstrate the porous spherical flower-like morphology, and spinel LiMn2O4shows the rod or rod clusters-like one with different particle sizes. The spinel LiMn2O4prepared from composite carbonate precursors delivers an initial discharge capacity of 115 mAh/g with excellent capacity retention, indicating an attractive application in the high-power lithium-ion batteries.


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