Multifunctional energy storage composites with built-in health monitoring capabilities
Abstract/Contents
- Abstract
- Vehicle electrification provides a means to transition away from fossil fuels. However, the widespread adoption of electric vehicles requires sustainable solutions to their short driving range, slow charging, high purchase cost, and safety concerns. Traditional research efforts have focused on developing new battery materials with higher energy densities which are inherently more mechanically fragile, undergo large volume expansion, and are difficult to monitor. These batteries in turn require proportionally larger weight overhead in the form of protection, restraining devices, and a contingency reserve capacity at the vehicle level. Thus, to maximize the performance of existing and new battery chemistries, it is desirable to i) make batteries more mechanically robust while maintaining minimal volume expansion and ii) accurately measure physical changes inside the battery and monitor battery health using built-in sensors. The first part of this work proposed and investigated a novel structurally-integrated Li-ion battery, called multifunctional energy storage composites (MESCs). MESCs encapsulate lithium-ion battery materials inside high-strength carbon-fiber composites using interlocking polymer rivets to mechanically stabilize the electrode layer stack. These rivets enable load transfer between battery layers, allowing them to contribute to load carrying capabilities. First-generation MESCs showed comparable electrochemical performance to standard lithium-ion cells, while also demonstrating significantly higher mechanical stiffness and the ability to restrain intercalation-induced expansion of electrodes. MESCs were also capable of maintaining their structural integrity and energy-storage capabilities under realistic repeated loading. The second part of this thesis developed and evaluated an acousto-ultrasonic system that measures battery state of charge and, in particular, its state of health using a built-in, low-profile piezoelectric transducer system. A diagnostic method was proposed that relates changes in the guided wave signals to the charge, discharge, and aging processes, via electrochemically-induced changes in mechanical properties. A matching-pursuit-based feature extraction scheme was developed to allow an efficient, in-operando decomposition of signals into a set of predictors correlated with battery states. A particle filter framework was established which provides state estimation and remaining life prognostics to allow ultrasonic features to be used as measurements. It was shown on several types of off-the-shelf batteries and MESCs that the ultrasonic technique significantly improved the prediction performance and contained uncertainties.
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource. |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2019; ©2019 |
| Publication date | 2019; 2019 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Ladpli, Purim |
|---|---|
| Degree supervisor | Chang, Fu-Kuo |
| Thesis advisor | Chang, Fu-Kuo |
| Thesis advisor | Senesky, Debbie |
| Thesis advisor | Springer, George S |
| Degree committee member | Senesky, Debbie |
| Degree committee member | Springer, George S |
| Associated with | Stanford University, Department of Aeronautics and Astronautics. |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Purim Ladpli. |
|---|---|
| Note | Submitted to the Department of Aeronautics and Astronautics. |
| Thesis | Thesis Ph.D. Stanford University 2019. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2019 by Purim Ladpli
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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