报告题目: |
Enabling high energy lithium ion batteries |
报告人: |
Dr. Wenquan Lu |
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Argonne National Laboratory, USA
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报告时间: |
2016-05-30 16:00 |
报告地点: |
化学工程系工物馆336教室 |
主办单位: |
化学工程系 |
简介: |
Title: Enabling high energy lithium ion batteries
Abstract
Many anode materials, including hard carbon, tin, tin oxide, silicon, and silicon oxide, have high theoretical capacities (>550 mAh/g) but tend to exhibit a large initial capacity loss (ICL). This is an important issue for the commercial application of some types of high capacity anodes in full LIBs that overrides the true reversible capacity of the anode itself. The existing strategies employed to address this issue usually involve adding different lithium sources to the anode, such as lithium powder or lithiated transition metal nitrides. Unfortunately, these strategies are not facile and may create safety issues in the practical application of LIBs. In this study, a new strategy is explored using a sacrificial lithium source additive, such as Li5FeO4, which in theory could release up to 5 lithium cations per mole to the cell upon first charge (equivalent to 867 mAh/g). As such, small amounts of LFO co-blended with the active cathode in conventional electrode laminate coatings could provide a solution to mitigate the ICL issues of anode with large ICL.
Conductive additive, such as carbon black, is very minor component and it is often overlooked. However, with stagnant development of active materials, the reduction of carbon black can make big impact on the improvement of cell energy density. In our lab, we reduced the loading of novel carbon black (Cabot) from 5 wt.% to 1 wt.% in the cathode, which increased the energy density of the electrode by 9% without sacrificing the electrochemical performance. In this work, we noticed that there is nonlinear conductivity of electrodes, which is significantly affected by the dispersion and surface crystalline quality of carbon black nanoparticles.
Biography
Dr. Wenquan Lu received his B.S. from Tsinghua University in 1995 and Ph. D from Illinois Institute of Technology in 2002. After working as postdoctoral at University of Virginia and Argonne National Laboratory, He joined Greatbatch to work on lithium primary batteries for implantable medical devices in 2006. Dr. Lu returned to Argonne as a staff scientist in 2008 and has been working on the lithium ion batteries for Electric Vehicle applications since then. His current focus is material characterization and energy storage system development.
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