Juchen GuoProfessor & Chair of MSE ProgramChemical Environ Engineering D juguo@ucr.edu(951) 827-6472
Dynamics of solvation effects on lithium-sulfur electrochemical processes in sub-nano confinement.
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AWARD NUMBER
008391-002
FUND NUMBER
33272
STATUS
Closed
AWARD TYPE
3-Grant
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AWARD EXECUTION DATE
6/28/2016
BEGIN DATE
7/1/2016
END DATE
6/30/2019
AWARD AMOUNT
$329,695
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Sponsor Information
SPONSOR AWARD NUMBER
SPONSOR
SPONSOR TYPE
FUNCTION
Organized Research
PROGRAM NAME
Proposal Information
PROPOSAL NUMBER
16030312
PROPOSAL TYPE
New
ACTIVITY TYPE
Basic Research
PI Information
PI
Guo, Juchen
PI TITLE
Other
PI DEPTARTMENT
Chemical/Environ. Engineering
PI COLLEGE/SCHOOL
Bourns College of Engineering
CO PIs
Wong, Bryan;
Project Information
ABSTRACT
1604908 PI: Guo
Title: Dynamics of solvation effects on lithium-sulfur electrochemical processes in sub-nano confinement
Lithium-sulfur (Li-S) batteries have the potential of providing higher energy density at a lower cost, when compared to the commercially available lithium-ion batteries. In contrast to Li-ion batteries that involve only solid state lithiation-delithiation reactions, Li-S batteries involve reactions in liquid electrolytes capable of dissolving lithium polysulfide (LPS) compounds in order to overcome the barriers posed by the highly insulating nature of sulfur. The performance of Li-S batteries is currently limited by the difference in the time scales of Li-S electrochemical reactions and LPS diffusion. The overarching goal of the proposed project is to investigate new electrode designs that enable the confinement of sulfur in sub-nanometer structures and eliminate the problems arising from LPS dissolution.
The key scientific objective of the proposed project is to understand the effects of confinement on the electrochemical behavior of sulfur in microporous carbon and single-walled carbon nanonutubes in order to improve the performance of Li-S batteries. In Li-S batteries, the lithiation-delithiation process requires a sequence of solid-liquid-solid reactions. The liquid electrolyte must dissolve the intermediate LPS compounds for high sulfur utilization, but some LPS is lost in each cycle through diffusion away from the electrode. Sub-nano confinement could overcome this challenge by blocking the solvent from entering the pores on the sulfur electrode, so Li+ ions can only enter the pores through desolvation, effectively immobilizing the Li-S reaction on the electrode surface. The proposed research will examine the fundamental mechanisms of Li-S electrochemistry with sub-nano confinement through a concerted experimental and modeling effort. In addition to training graduate students, the PIs plan to involve undergraduate students in research and propose an outreach effort focused at engaging underrepresented minority students from the Rialto Unified School District High Schools. The outcome of this research project may have a broader impact on the field of sub-nano confinement in porous nanostructures.(Abstract from NSF)
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