The optimization of porosity and particle size for micron-size porous silicon in high energy pre-lithiated silicon-graphite composite for Li-ion batteries

Author(s):  
Yiteng Luo ◽  
Liwu Huang ◽  
Jianbo Liu ◽  
Zerui Wang ◽  
Qinghao Chen ◽  
...  
Author(s):  
Malcolm Stein ◽  
Chien-Fan Chen ◽  
Matthew Mullings ◽  
David Jaime ◽  
Audrey Zaleski ◽  
...  

Particle size plays an important role in the electrochemical performance of cathodes for lithium-ion (Li-ion) batteries. High energy planetary ball milling of LiNi1/3Mn1/3Co1/3O2 (NMC) cathode materials was investigated as a route to reduce the particle size and improve the electrochemical performance. The effect of ball milling times, milling speeds, and composition on the structure and properties of NMC cathodes was determined. X-ray diffraction analysis showed that ball milling decreased primary particle (crystallite) size by up to 29%, and the crystallite size was correlated with the milling time and milling speed. Using relatively mild milling conditions that provided an intermediate crystallite size, cathodes with higher capacities, improved rate capabilities, and improved capacity retention were obtained within 14 μm-thick electrode configurations. High milling speeds and long milling times not only resulted in smaller crystallite sizes but also lowered electrochemical performance. Beyond reduction in crystallite size, ball milling was found to increase the interfacial charge transfer resistance, lower the electrical conductivity, and produce aggregates that influenced performance. Computations support that electrolyte diffusivity within the cathode and film thickness play a significant role in the electrode performance. This study shows that cathodes with improved performance are obtained through use of mild ball milling conditions and appropriately designed electrodes that optimize the multiple transport phenomena involved in electrochemical charge storage materials.


2009 ◽  
Vol 289-292 ◽  
pp. 565-570 ◽  
Author(s):  
W. Iwaniak ◽  
J. Fritzsche ◽  
M. Zukalová ◽  
R. Winter ◽  
Martin Wilkening ◽  
...  

Spinel-type structured Li4+xTi5O12 (0 6 x 6 3 ) is actually one of the most promising anode materials for Li ion batteries. In its nanostructured form it is already used in some commercially available Li ion batteries. As was recently shown by our group (Wilkening et al., Phys. Chem. Chem. Phys. 9 (2007) 1239), Li diffusivity in microcrystalline Li4+xTi5O12 with x = 0 is rather slow. In the present contribution the Li conductivity in nanocrystalline samples of the electronic insulator Li4Ti5O12 prepared by different routes is investigated using impedance spectroscopy. The mean crystallite size of the samples is about 20 nm. The ionic conductivity of nanocrystalline Li4Ti5O12 obtained by mechanical treatment is higher by about two orders of magnitude compared to that found for a material which was prepared following a sol-gel method. The latter resembles the behaviour of the microcrystalline sample with an average particle size in the μm range rather than that of a nanocrystalline ball milled one with a mean crystallite size of about than 20 nm. The larger conductivity of the ball milled sample is ascribed to a much higher defect density generated when the particle size is reduced mechanically.


2021 ◽  
Vol 9 (14) ◽  
pp. 9337-9346
Author(s):  
Erhong Song ◽  
Yifan Hu ◽  
Ruguang Ma ◽  
Yining Li ◽  
Xiaolin Zhao ◽  
...  

Li-rich layered cathodes based on Li2MnO3 have exhibited extraordinary promise to satisfy the rapidly increasing demand for high-energy density Li-ion batteries.


2021 ◽  
Vol 415 ◽  
pp. 128509
Author(s):  
Qihang Yu ◽  
Wu Tang ◽  
Yang Hu ◽  
Jian Gao ◽  
Ming Wang ◽  
...  

Author(s):  
Partha P. Paul ◽  
Chuntian Cao ◽  
Vivek Thampy ◽  
Hans-Georg Steinrück ◽  
Tanvir R. Tanim ◽  
...  

2019 ◽  
Vol 17 ◽  
pp. 136-142 ◽  
Author(s):  
Changmin Shi ◽  
Tianyang Wang ◽  
Xiangbiao Liao ◽  
Boyu Qie ◽  
Pengfei Yang ◽  
...  

2011 ◽  
Vol 282-283 ◽  
pp. 82-85
Author(s):  
Xiao Peng Ji ◽  
Xing Feng Guan ◽  
Zhen Hong Wang

Li-ion batteries have been widely used. However, the safety concern is always serious due to its high energy density. In order to improve the safety of the batteries, it is necessary to use the protection integration circuit. In this article, the concept for realizing the safety protection of Li-ion batteries during charging and discharging is described briefly. A circuit design using Seiko BMS chip S-8209 is purposed. Based on this, a simulation was performed and verified using Pspice program, which provides a theoretical basis for the circuit design.


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