GOALI: Understanding and Controlling Coupled Mechanical and Chemical Degradation Phenomena within Insertion Electrodes

Grants and Contracts Details

Description

Project Summary The objectives of this proposal are to understand and, ultimately, control one of the poorly understood problems in electrochemical energy storage, namely the coupled mechanical and chemical degradation in lithium ion batteries. The research is critically important to developing more powerful and longer lasting lithium ion batteries. As a result of lithium insertion and de-insertion, fracture and decrepitation can occur which limit the durability of lithium ion batteries. Fracture can also prevent electrode materials from achieving their theoretically high energy and power densities. Furthermore, fracture of the Solid- Electrolyte Interphase of a few nanometers thick is believed responsible for the coupled chemicalmechanical degradation of lithium ion battery electrodes. Intellectual Merit: Recent collaborative work at the University of Kentucky and General Motors R&D Center on modeling diffusion-induced stresses in insertion electrodes suggests new opportunities for systematically exploring the effects of diffusion coefficients, surface reaction rates, bulk and surface mechanical properties on fracture and decrepitation of insertion electrodes. It also hints the possibility of linking the state-of-charge, stress-amplitude, and durability of electrodes, thus enabling battery life prediction and health monitoring. In this proposed work, various assumptions and predictions from the preliminary modeling work will be systematically examined through novel experiments based on in-situ charge, mass, and stress measurements using electrochemical quartz crystal oscillators. The formation of cracks leading to decrepitation will also be studied using ex-situ observations using a unique focused-ionbeam/ secondary-ion-mass-spectrometry system. The findings from the proposed experiments will be used to further advance the coupled mechanical/chemical degradation models for insertion electrodes. The proposed work should form the basis for surface engineering approaches to control stresses and mitigate the coupled mechanical/chemical degradation in insertion electrodes. This work will also help establish materials selection criteria for high capacity and durable lithium ion batteries. The knowledge gained from the work will ultimately lead to synthetic control of materials’ architectures at the nanoscale which will result in transformational breakthroughs to overcome the coupled mechanical/chemical degradation of insertion electrodes. Broader impacts: Batteries have, in the past, been the focus of electrochemists, including solid-state electrochemists, who have made tremendous contributions to the state-of-art battery technologies. However, recent advances in battery technologies have highlighted the multi-disciplinary and interdisciplinary nature of the field. To take the technology farther will require the advancement of new knowledge at the intersections of electrochemistry, mechanics of materials, thermal sciences, chemistry, and physics. The coupled mechanical and chemical degradation of batteries is such an example. The proposed work will help advance the understanding of coupled phenomena in electrochemistry and mechanics of materials. It will also help train people with deep knowledge and broad experience at the confluence of these fields. The proposed research activities on coupled electrochemical/mechanical phenomena will directly impact a number of critical technological areas that depend on energy storage, including automotive, aerospace, electronics, and communication. It will also benefit other areas such as sensors for environmental monitoring and biosensors for medical applications. The proposed research will help train postdocs and graduate students in an academic-industrial lab setting. A new course will be developed and offered to students of both Chemical Engineering and Materials Engineering programs in the Department of Chemical and Materials Engineering at the University of Kentucky. This new course will be developed jointly with researchers at GM R&D Center. Some of the lectures will be given at GM as part of its continuing education program. The proposed research will also be integrated into undergraduate research: undergraduates at UK will have hands-on lab experience through existing and new courses and an existing Nanoscale Engineering Certificate Degree program. They will have opportunity to visit and work at GM R&D Center for the project. The in-situ charge, mass, and stress measurement methods will also be used by some of the projects of on-going NSF IGERT and REU programs on Engineered Bioactive Interfaces and Devices, especially on electrochemical and mechanical characterization of novel biomaterials and the interaction of cells with surfaces.
StatusFinished
Effective start/end date6/1/10 → 11/30/14

Funding

  • National Science Foundation: $325,000.00

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