scholarly journals Understanding inks for porous-electrode formation

2017 ◽  
Vol 5 (39) ◽  
pp. 20527-20533 ◽  
Author(s):  
Kelsey B. Hatzell ◽  
Marm B. Dixit ◽  
Sarah A. Berlinger ◽  
Adam Z. Weber
Keyword(s):  
Energy Storage ◽  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Porous Electrode ◽  
Energy Storage And Conversion ◽  
Electrode Performance ◽  
Colloidal State

Scalable manufacturing of high-aspect-ratio multi-material electrodes are important for advanced energy storage and conversion systems. There is a need to understand how one goes from a colloidal state through processing to a functional porous electrode. Such knowledge enables ink-engineering for electrode performance and durability optimization.

Enhanced Energy Storage in Nanocomposites Through Aligned PZT Nanowires

2011 ◽  
Author(s):  
Haixiong Tang ◽  
Henry A. Sodano ◽  
Yirong Lin
Keyword(s):  
Energy Storage ◽  
Energy Density ◽  
Dielectric Permittivity ◽  
Aspect Ratio ◽  
Electric Field ◽  
Applied Electric Field ◽  
Energy Storage And Conversion ◽  
Electromechanical Properties ◽  
Capacitive Energy Storage ◽  
Wide Range

Nanocomposites consisting of a piezoceramic inclusion and polymer matrix offer a combination of electromechanical coupling with high toughness and ductility inherent to polymers. There is a wide range of applications for these types of materials due to their intrinsic piezoelectric and dielectric properties, such as vibration sensing, actuation, energy harvesting and capacitive energy storage. However, the relatively low piezoelectric strain coefficient and dielectric permittivity of these nanocomposites significantly limit their application in energy conversion and energy storage applications. There are mainly two coupled to improve the dielectric permittivity and electromechanical properties of piezoceramic nanocomposites, namely higher aspect ratio active inclusions and alignment of inclusions in the direction of the applied electric field. Previously, we have demonstrated that using higher aspect ratio lead zirconate titanate (PZT) nanowires (NWs) could significantly enhance the energy density and d33 coupling as compared to the samples with lower aspect ratio PZT nanorods [11]. In this paper, we will show that orientation of PZT NWs also influences energy storage capability of nanocomposite. Nanocomposites with aligned PZT NWs in the direction of the applied electric field show increased dielectric permittivity and energy density as compared to those with randomly dispersed inclusions. PZT NWs are hydrothermally synthesized, dispersed into a polyvinylidene fluoride (PVDF), cast into a film and then aligned through uniaxial stretching. Scanning electric microscopy (SEM) shows the PZT NWs are successfully aligned in direction of stretching. This work demonstrates that the energy storage and conversion capability of the nanocomposite can be significantly enhanced through the alignment of PZT NWs in the direction of the applied electric field. The findings of this research could lead to broad interest due to demonstration of developing piezoceramic nanocomposites with enhanced dielectric and electromechanical properties for next generation energy storage and conversion devices.

Numerical Simulation of Thermal Performance of a High Aspect Ratio Thermal Energy Storage Device

2012 ◽  
Author(s):  
Jingde Zhao ◽  
Jorge L. Alvarado ◽  
Ehsan M. Languri ◽  
Chao Wang
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Energy Storage ◽  
Aspect Ratio ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
High Aspect Ratio ◽  
Numerical Study ◽  
Experimental Results ◽  
Heat Transfer Analysis

Heat transfer analysis of a high aspect ratio thermal energy storage (TES) device was carried out numerically. The three dimensional numerical study was performed to understand the heat transfer enhancement which results from internal natural convection in a high aspect ratio vertical unit. Octadecane was used as phase change material (PCM) inside TES system, which consisted of six corrugated panels filled with PCM. Each panel had a total of 6 tall cavities filled with PCM, which were exposed to external flow in a concentric TES system. Unlike traditional concentric-type TES devices where heat transfer by conduction is the dominant heat transport mechanism, the high aspect ratio TES configuration used in the study helped promote density-gradient based internal convection mechanism. The numerical model was solved based on the finite volume method, which captured the whole transient heat transfer process effectively. The time-dependent temperature profiles of the PCM inside a single TES panel are compared with the experimental results for two cases. Numerical and experimental results of the two cases showed a reasonable agreement. Furthermore, convection cells were formed and sustained when the PCM melted within the space between the solid core and the walls. The promising results of this numerical study illustrate the importance of internal natural convection on the speed of the PCM melting (charging) process.

Sign in / Sign up

Export Citation Format

Share Document