ORAL

SESSION: MultiscaleThuAM-R3	4th Intl. symp. on Multiscale Material Mechanics and Multiphysics and Sustainable Applications
Thu Oct, 26 2017	Room: Peninsula 1
Session Chairs: K.Y. Xu; Mei Zhang; Session Monitor: TBA

11:00: [MultiscaleThuAM01] Invited
Nanocarbon Foams: Fabrication, Characterization, and Application
Mei Zhang¹ ; ¹Florida State University, Tallahassee, United States;
Paper Id: 313 [Abstract]

Nanocarbon foam is a carbon nanotube based all carbon porous material. It consists of large numbers of micro-scale cells and sub-micro thick walls with nano-scale pores. Because of their unique structures, the nanocarbon foams show high capillary pressure, super-absorption, large working fluid storage, and fast fluid transfer capabilities. They are also conductive, lightweight, stable, and flexible. These features allow nanocarbon foams to be a novel wick material for thermal management products and have a better performance than current wick materials. The simple and scalable fabrication process could lead to low cost and high quality device manufacturing. The lightweight, super-elastic, and high stability properties of nanocarbon foams make them a unique alternative for the thermal management of portable and flexible electronic devices. In addition to thermal management, other applications of nanocarbon foams include use in electrodes for advanced batteries, in fuel cells, in pressure sensors, and in scaffolds for medical treatments. The detailed fabrication process, property characterization, and potential applications will be presented.

SESSION: BatteryTueAM-R4	4th Intl. Symp. on Sustainable Secondary Battery Manufacturing and Recycling
Tue Oct, 24 2017	Room: Peninsula 4
Session Chairs: Tetsuya Yamada; Katsuya Teshima; Session Monitor: TBA

11:30: [BatteryTueAM02] Invited
Energy Density Limitation of Lithium-Sulfur Batteries
Chao Shen¹ ; Jianxin Xie¹ ; Mei Zhang¹ ; Petru Andrei¹ ; Jim Zheng¹ ; ¹Florida State University, Tallahassee, United States;
Paper Id: 343 [Abstract]

Lithium-sulfur (Li-S) batteries are among the most promising candidates for the next generation rechargeable batteries due to their high energy density, low raw material cost and environmental friendliness. Although Li-S batteries possess a high theoretical cathode specific capacity of 1,672 mAh g-1, the energy density of practical Li-S batteries is much smaller and depends on electrolyte/sulfur (E/S in mL g-1) ratio. From previous works, successful operation of Li-S batteries under lean electrolyte conditions can be challenging, especially in the case when the solubility of lithium polysulfide (LiPS) sets an upper bound for polysulfide dissolution. Very recently, we have demonstrated that the E/S ratio of Li-S cells has a significant effect on both performance and theoretical energy density of Li-S batteries. Since the lower-bound for E/S ratio is restricted by the solubility of LiPS in the organic electrolyte, the theoretical energy density of Li-S batteries is significantly reduced. Experimentally, it was approved that when the LiPS concentration reached to the solubility limitation in the electrolyte, the reaction rate of reducing sulfur to LiPS in the cathode will reduce significantly. In this talk, we will discuss the relationship between theoretical specific energy and the solubility of LiPS in the electrolyte. The experiments were also proved that the solubility of LiPS could be the ultimate limitation to the energy density of Li-S batteries.