报告题目：Novel carbon materials and their application in energy conversion and storage
报告时间：2017年5月18日（星期四）15:00
报告地点：东院图书馆一楼学术报告厅
报 告 人：吴英鹏 博士
报告人简介：
吴英鹏，男，2007年上海交通大学高分子材料专业本科毕业,2012年获得南开大学博士学位，师从陈永胜教授。曾在美国斯坦福大学戴宏杰院士课题组从事博士后研究工作。现在威斯康辛州立大学密尔沃基分校任Research Associate。长期从事植碳纳米材料的制备与应用研究，在石墨烯制备及其在能量存储与转化领域开展了多项开拓性研究，取得了多项创新成果。作为文章第一作者，在世界上首次完成了高弹性零泊松比石墨烯材料的发明，文章发表在Nature Communication；作为骨干研究成员和文章共同第一作者，在世界上首次完成了长寿命高倍率铝离子电池的发明，文章发表在Nature；作为文章共同第一作者，在世界上首次完成了宏观光驱动石墨烯发明，文章发表在Nature photonics；以上工作被国内外媒体广泛报道，包括人民日报， Stanford University News Home, CCTV, ABC, CNN等。此外，在石墨烯的制备及应用方面进行了多项工作，成果发表在Advanced Materials, Nano Energy等高影响力杂志。
报告内容
We report the scalable self-assembly of randomly oriented graphene sheets into additive-free, essentially homogenous graphene sponge materials that provide a combination of both cork-like and rubber-like properties. These graphene sponges, with densities similar to air, display Poisson’s ratios in all directions that are near-zero and largely strain-independent during reversible compression to giant strains. And at the same time, they function as enthalpic rubbers, which can recover up to 98% compression in air and 90% in liquids, and operate between 196 and 900℃. Furthermore, these sponges provide reversible liquid absorption for hundreds of cycles and then discharge it within seconds, while still providing an effective near-zero Poisson’s ratio.
With this novel material, direct light propulsion of matter is observed on a macroscopic scale. The unique structure and properties of graphene, and the novel morphology of the bulk three-dimensional linked graphene material make it capable not only of absorbing light at various wavelengths but also of emitting energetic electrons efficiently enough to drive the bulk material, following Newtonian mechanics. Thus, the unique photonic and electronic properties of individual graphene sheets are manifested in the response of the bulk state. These results offer an exciting opportunity to bring about bulk-scale light manipulation with the potential to realize long-sought applications in areas such as the solar sail and space transportation driven directly by sunlight.
A rechargeable aluminum battery with high-rate capability that uses an aluminum metal anode and a three-dimensional graphitic-foam cathode. The battery operates through the electrochemical deposition and dissolution of aluminum at the anode, and intercalation/de-intercalation of chloroaluminate anions in the graphite, using a non-flammable ionic liquid electrolyte. The cell exhibits well-defined discharge voltage plateaus near 2 volts, a specific capacity of about 70mAh g–1 and a Coulombic efficiency of approximately 98 percent. The cathode was found to enable fast anion diffusion and intercalation, affording charging times of around one minute with a current density of 4,000mAg–1 (equivalent to 3,000Wkg–1), and to withstand more than 7,500 cycles without capacity decay. Based on the aluminum battery, a novel 3D graphitic foam was derived through chloroaluminate anion intercalation of graphite followed by thermal expansion and electrochemical hydrogen evolution in the pores of graphitic sheets. The approach avoided extensive irreversible oxidation of graphite and prevented introduction of large amounts of oxidation-induced defects into the graphene sheets. The 3DGF was the ability of orienting vertically aligned graphene sheets perpendicular to a current collector substrate to facilitate electrochemical reactions and processes. This aligned 3DGF afforded a cathode for rechargeable Al-ion battery with a discharge capacity of ~60 mAh g-1 at a high current charge/discharge density up to 12 000 mA g-1 stably cycled over 4000 cycles.
