Nano-structured electrode concepts for high-performance lithium-ion batteries
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Authors
Mukherjee, Rahul
Issue Date
2014-12
Type
Electronic thesis
Thesis
Thesis
Language
ENG
Keywords
Mechanical engineering
Alternative Title
Abstract
Finally, the mechanism of lithium-graphene interaction, based on a defect-induced lithium metal plating in graphene, was extended to synthesize a new class of electrode materials. It was observed that in porous graphene structures, lithium metal plating occurred within the nano-pores and were strictly contained within these nano-pores. It was confirmed through extensive cycling and characterization that the lithium metal plating in graphene is indeed benign and does not lead to the formation of dendrites, therefore assuring the safety characteristics of the graphene-lithium electrode. The advantage of the graphene-lithium electrode, when used as the source of lithium ions in a lithium ion battery (conventionally referred to as the cathode), is that it allows for a much higher capacity to be achieved. Lithium metal is known to be able to provide capacities as high as 3840 mAh/g. However, pure lithium metal is not used in lithium ion batteries due to safety concerns associated with dendritic outgrowths. Instead, commer-cial cathodes use complex chemical matrices such as lithium cobalt oxides, phospho-olivines such as lithium iron phosphates or spinels such as lithium manganese oxides. However, commercial cathodes have a much lower capacity, ranging from 150-200 mAh/g while the graphene-lithium composite could provide capacities as high as 850 mAh/g. Therefore, the graphene-lithium composite electrode provides an opportunity to drastically improve the achievable capacity of lithium ion batteries. Importantly, the graphene-lithium composite electrodes also eliminate toxic and expensive metals like cobalt, nickel, aluminum and copper, commonly used in present-day lithium ion batteries, therefore enabling a lighter, cheaper and environmentally sustainable next-generation lithium ion battery.
Description
December 2014
School of Engineering
School of Engineering
Full Citation
Publisher
Rensselaer Polytechnic Institute, Troy, NY