Very High Surface Capacity with Si Negative Electrodes Embedded in Copper Foam as 3D Current Collector

2014 ◽  
Vol 4 (8) ◽  
pp. 1301718 ◽  
Author(s):  
Driss Mazouzi ◽  
David Reyter ◽  
Magali Gauthier ◽  
Philippe Moreau ◽  
Dominique Guyomard ◽  
...  

2018 ◽  
Vol 115 (6) ◽  
pp. 1156-1161 ◽  
Author(s):  
Liumin Suo ◽  
Weijiang Xue ◽  
Mallory Gobet ◽  
Steve G. Greenbaum ◽  
Chao Wang ◽  
...  

Lithium metal has gravimetric capacity ∼10× that of graphite which incentivizes rechargeable Li metal batteries (RLMB) development. A key factor that limits practical use of RLMB is morphological instability of Li metal anode upon electrodeposition, reflected by the uncontrolled area growth of solid–electrolyte interphase that traps cyclable Li, quantified by the Coulombic inefficiency (CI). Here we show that CI decreases approximately exponentially with increasing donatable fluorine concentration of the electrolyte. By using up to 7 m of Li bis(fluorosulfonyl)imide in fluoroethylene carbonate, where both the solvent and the salt donate F, we can significantly suppress anode porosity and improve the Coulombic efficiency to 99.64%. The electrolyte demonstrates excellent compatibility with 5-V LiNi0.5Mn1.5O4 cathode and Al current collector beyond 5 V. As a result, an RLMB full cell with only 1.4× excess lithium as the anode was demonstrated to cycle above 130 times, at industrially significant loading of 1.83 mAh/cm2 and 0.36 C. This is attributed to the formation of a protective LiF nanolayer, which has a wide bandgap, high surface energy, and small Burgers vector, making it ductile at room temperature and less likely to rupture in electrodeposition.


2003 ◽  
Vol 788 ◽  
Author(s):  
A. Akash ◽  
B. Nair ◽  
K. Minnick ◽  
M. Wilson ◽  
J. Hartvigsen

ABSTRACTA novel nano-ceramic material, called HSA-CERCANAM®, which has a very high surface area with a nanopore network has been developed. HSA-CERCANAM® can be casted in various shapes and forms resulting in a monolithic piece that has surface area as high as 80–100 m2/g. The surface area and the nanopore network of HSA-CERCANAM® remains stable at temperatures as high as 1000°C. Furthermore, the unique nature of HSA-CERCANAM® allows it to be casted on and around features, either sacrificial or permanent. Using sacrificial features, microchannels can be incorporated internally into the monolithic HSA-CERCANAM® piece in a simple, one-step process. Further, this monolithic ceramic component, which has an intrinsically high surface area and a nanopore network, can be infiltrated with a desired catalyst. This could offer clear technological advantages over currently available microreactors. The surface area, porosity, catalyst type and infiltration levels are some of the ways in which tailored microstructures can be realized in components such as mixers, heat exchangers, extractors, filters or reaction chambers thereby leading to highly efficient, multi-functional ceramic micro-devices.


Author(s):  
Aizoh Kubo

Some typical examples of failure of gears made from very high strength steel are shown and its trigger and whose causes are discussed: Many of such failure are triggered by tooth side edge contact or tooth tip edge contact and meshing-in of the wear debris. The limit of validity of the traditional methods for load carrying capacity of gears exists in the fact that they are based on the theory of contact of tooth flanks that realize conjugate or almost conjugate action of gears. To be able to design reliable gears made from very high strength steel, a principle is shown that suggests a new method for tooth form modification and of longitudinal crowing modification to avoid such failure. Metallurgical problem of gear material and special heat treatment aiming high surface hardness is also discussed.


2019 ◽  
Vol 7 ◽  
Author(s):  
Juan Yu ◽  
Yangyang Dang ◽  
Maohui Bai ◽  
Jiaxin Peng ◽  
Dongdong Zheng ◽  
...  

Batteries ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 21 ◽  
Author(s):  
Huajun Feng ◽  
Yuan Chen ◽  
Yihua Wang

In this work, we use ultrasonication and chemical etching agents to assist preparation of metal current collectors with nano-scale pores on the surface. Four different current collectors (copper foil, copper foam, aluminum foil, and aluminum foam) are prepared. The preparation parameters, ultrasonic time and etching agent concentration, are investigated and optimized accordingly. The morphologies of the as-prepared current collectors are observed under a scanning electronic microscope. Soft-packed lithium ion batteries with various current collectors are fabricated and tested. The prepared lithium ion batteries show good long-term cycle stability. The nanoporous structure of the current collector has little impact on the improvement of battery capacity under slow charging/discharging rates but has a positive impact on capacity retention under fast charging/discharging rates.


2016 ◽  
Vol 23 (5) ◽  
pp. 1227-1237 ◽  
Author(s):  
Haribandhu Chaudhuri ◽  
Subhajit Dash ◽  
Ashis Sarkar

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