Design and Fabrication of High Energy Density Lithium Battery

Abstract

Rechargeable LIBs have been widely used in many portable consumer electronics. They presently have limited acceptance in larger energy storage markets, e.g., plug-in hybrid and electrical vehicles due to several issues, including 1) low energy density or power density, 2) poor cycling stability, 3) safety concerns about lithium-ion batteries.EC Power has been working on development of novel polymer-carbon nanocomposite cathode materials to demonstrate high energy/power Li-ion batteries using the electrode materials. A series of polymers with electrochemically active functional groups have been synthesized, characterized, and fabricated as cathode for lithium batteries. The polymer cathode has showed high capacity up to 250mAh/g and the long cycling performance up to 500 cycles. Compared to the traditional cathode materials, the polymer cathode materials not only have high specific capacity, but also are potentially low-cost and recyclable.In order to study the degradation of the battery cells, EC Power also designed and fabricated 3-electrode cells. With the lithium reference, we are able to test and observe the voltage profile of cathode, anode and the full cell, respectively. Thus we will be able to study the degradation behavior of the cathode and anode respectively in the full cell environment. The degradation behavior of cathode and anode in a full cell is different from that in a half-cell. The study help us to understand the kinetics of full cell chemistry, target the control step in degradation and thus to mitigate the degradation.In this presentation, we will also demonstrate several complimentary methods for fabrication of commercially viable size cells of the Li-polymer and conventional Li-ion batteries with the process much faster and cost-effective. With the EC Power’s proprietary cell design software, which gives us a very reasonable starting point for expected cell performance upon cell fabrication, EC Power has successfully fabricated different types of cells.