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.

Developing new techniques to synthesize layered cathode materials for lithium-ion batteries

2019 ◽  
Author(s):  
◽  
Khaleel Idan Hamad
Keyword(s):  
Discharge Capacity ◽  
Cathode Materials ◽  
Sol Gel ◽  
Lithium Ion ◽  
Capacity Fade ◽  
Nitrate Salt ◽  
Initial Discharge Capacity ◽  
Capacity Retention ◽  
Initial Discharge ◽  
Co Precipitation

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.

Effects of K in Mn2O3 on the Electrochemical Performances of Spinel Li1.06Mn2O4

2013 ◽  
Vol 773 ◽  
pp. 611-616
Author(s):  
Xing Zou ◽  
Chun Lin Peng
Keyword(s):  
Discharge Capacity ◽  
Retention Rate ◽  
Lithium Ion ◽  
Cycle Performance ◽  
Manganese Carbonate ◽  
Electrochemical Performances ◽  
Initial Discharge Capacity ◽  
Doping Amount ◽  
Capacity Retention ◽  
Initial Discharge

Spinel LiMn2O4 material is one of the lithium-ion battery cathodes. It is cheap, nontoxic, and safe in use. This cathode material, Li1.06Mn2O4 was synthesized by using solid state reaction and two different starting materials. One was the Mn2O3 made from the industrial manganese carbonate with different contents of potassium, and the other was the high-purity Mn2O3 into which the same amount of potassium in the form of K2CO3 was added to form the K-doped spinel Li1.06Mn2O4. These two kinds of LiMn2O4 materials were characterized by XRD, SEM and electrochemical performance analysis. The results showed that the initial discharge capacity of the former cathode materials decreased gradually and the cycle performance was improved with the amount of potassium increasing. The Li1.06Mn2O4 with a content of 192.2 μg.g-1 of potassium presented the optimized electrochemical performances, with an initial discharge capacity of 128.974mAh.g-1, and a capacity retention rate of 89.90% after 50 cycles. The initial discharge capacity of doped Li1.06Mn2O4 dropped rapidly with the doping amount increasing and the capacity retention rate was not as good as that of the Mn2O3 made from the industrial manganese carbonate with different contents of potassium.

An inorganic–organic nanocomposite calix[4]quinone (C4Q)/CMK-3 as a cathode material for high-capacity sodium batteries

2017 ◽  
Vol 4 (11) ◽  
pp. 1806-1812 ◽  
Author(s):  
Shibing Zheng ◽  
Jinyan Hu ◽  
Weiwei Huang
Keyword(s):  
Cathode Material ◽  
Discharge Capacity ◽  
High Capacity ◽  
Initial Discharge Capacity ◽  
Capacity Retention ◽  
Initial Discharge ◽  
Sodium Batteries

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.

scholarly journals Synthesis and Electrochemical Properties of C/LiMnPO4 Cathode Materials by Complex Polymerized Method

2011 ◽  
Vol 485 ◽  
pp. 115-118
Author(s):  
Atsushi Fujita ◽  
Fuminari Isobe ◽  
Takayuki Kodera ◽  
Takashi Ogihara
Keyword(s):  
Thermogravimetric Analysis ◽  
Electrochemical Properties ◽  
Carbon Content ◽  
Discharge Capacity ◽  
Cathode Materials ◽  
Type Structure ◽  
Initial Discharge Capacity ◽  
Initial Discharge ◽  
Differential Thermogravimetric Analysis

C/LiMnPO4 materials were synthesized by the complex polymerized method. An orthorhombic olivine type structure was obtained by calcination at temperatures over 973 K under an argon/hydrogen (5%) atmosphere. Differential thermogravimetric analysis showed that the carbon content of C/LiMnPO4 was about 65 wt%. The initial discharge capacity of C/LiMnPO4 calcined at 973 K was 135 mAh/g at 0.1 C and 60 mAh/g at 1 C.

scholarly journals Excellent Temperature Performance of Spherical LiFePO4/C Composites Modified with Composite Carbon and Metal Oxides

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Bao Zhang ◽  
Tao Zeng ◽  
Jiafeng Zhang ◽  
Chunli Peng ◽  
Junchao Zheng ◽  
...  
Keyword(s):  
Low Temperature ◽  
Room Temperature ◽  
Electrochemical Performances ◽  
Initial Discharge Capacity ◽  
Sintering Process ◽  
Capacity Retention ◽  
Voltage Range ◽  
Temperature Performance ◽  
Initial Discharge ◽  
Composite Carbon

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.

LiNi0.5Mn1.5O4 microcubes: cathode materials with improved discharge/charge performances for lithium-ion batteries

CrystEngComm ◽  
2019 ◽  
Vol 21 (3) ◽  
pp. 399-402
Author(s):  
Yanli Fu ◽  
Liqiong Wu ◽  
Shengang Xu ◽  
Shaokui Cao ◽  
Xinheng Li
Keyword(s):  
Lithium Ion Batteries ◽  
Discharge Capacity ◽  
Cathode Materials ◽  
Lithium Ion ◽  
Interfacial Effect ◽  
Initial Discharge Capacity ◽  
Initial Discharge

LiNi0.5Mn1.5O4 microcubes grown from nanowires delivered an initial discharge capacity of 123 mAh g−1 at 1C and maintained 95% of the capacity after 50 cycles due to interfacial effect.

Fabrication of layered Ti3C2 with an accordion-like structure as a potential cathode material for high performance lithium–sulfur batteries

2015 ◽  
Vol 3 (15) ◽  
pp. 7870-7876 ◽  
Author(s):  
Xiaoqin Zhao ◽  
Min Liu ◽  
Yong Chen ◽  
Bo Hou ◽  
Na Zhang ◽  
...  
Keyword(s):  
Cathode Material ◽  
Discharge Capacity ◽  
High Performance ◽  
Coulombic Efficiency ◽  
Initial Discharge Capacity ◽  
Capacity Retention ◽  
Initial Discharge ◽  
Lithium Sulfur Batteries ◽  
Lithium Sulfur

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.

Solvothermal Synthsis of Nano-Sized Li4Ti5O12 Particles as Anode Material for Lithium Ion Batteries

2015 ◽  
Vol 1120-1121 ◽  
pp. 281-285 ◽  
Author(s):  
Yue Zhang ◽  
Yu Jing Zhu ◽  
Yuan Xiang Gu ◽  
Rui Xin Chen
Keyword(s):  
Lithium Ion Batteries ◽  
Anode Material ◽  
Discharge Capacity ◽  
Solvothermal Method ◽  
Rate Capability ◽  
Lithium Ion ◽  
Electrochemical Measurements ◽  
Initial Discharge Capacity ◽  
Initial Discharge

We synthesized nano-Li4Ti5O12 particles by solvothermal method. The as-prepared materials were characterized by XRD, SEM, TEM and electrochemical measurements. The Li4Ti5O12Li4Ti5O12 showed excellent rate capability and cycle ability. The as-preparedLi4Ti5O12 Li4Ti5O12 electrode exhibited highly initial discharge capacity 176 mAh/g at 0.1 C rate up to, which was slightly higher than its theoretical capacity (175 mAh/g). By increasing the C-rate, the cell showed 152, 143, 138 and 135 mAh/g at 0.5, 1, 1.5 and 2 C, respectively.

Mg doped Li2FeSiO4/C nanocomposites synthesized by the solvothermal method for lithium ion batteries

2017 ◽  
Vol 46 (38) ◽  
pp. 12908-12915 ◽  
Author(s):  
Ajay Kumar ◽  
O. D. Jayakumar ◽  
Jagannath Jagannath ◽  
Parisa Bashiri ◽  
G. A. Nazri ◽  
...  
Keyword(s):  
Carbon Content ◽  
Lithium Ion Batteries ◽  
Discharge Capacity ◽  
Solvothermal Method ◽  
Rate Capability ◽  
Lithium Ion ◽  
Initial Discharge Capacity ◽  
Cycle Stability ◽  
Initial Discharge ◽  
Mg Doped

Despite having the same carbon content, Li2Fe0.99Mg0.01SiO4/C delivered the highest initial discharge capacity and also exhibited the best rate capability and cycle stability.

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