Integrated Actuation and Thermal Management of Lithium Ion Batteries
Restricted (Penn State Only)
- Author:
- Longchamps, Ryan
- Graduate Program:
- Mechanical Engineering
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- August 19, 2022
- Committee Members:
- Alexander Rattner, Major Field Member
Chris Rahn, Major Field Member
Chao-Yang Wang, Chair & Dissertation Advisor
Daniel Connell Haworth, Professor in Charge/Director of Graduate Studies
Mehdi Kiani, Outside Unit & Field Member - Keywords:
- Battery
Thermal Management
Lithium-ion
Electric vehicles
Battery safety
Battery actuation
Thermal Modulation
Self-heating - Abstract:
- The unparalleled performance of lithium-ion batteries (LIBs) is driving the ongoing trend of vehicle electrification. However, expanding performance expectations continue to extend the list of “and problems” that require one battery technology to perform many roles that often conflict with each other and are impractical with existing materials. Recently, battery structure modification for internal heating has enabled rapid and efficient thermal modulation of battery performance. This structure, termed the self-heating battery (SHB), achieved restoration of power levels practical for plug-in hybrid electric vehicle batteries in -40 °C ambient conditions. What’s more, when adopted for pre-heating to an elevated temperature, 10-minute extreme fast charging was enabled without sacrificing lifetime. In this dissertation, the SHB structure is studied for its applicability to electric vehicle LIBs, which conventionally meet energy density requirements for long range at the cost of stifled power performance. This serves to expand the generality of SHB application at ultra-cold temperatures (e.g., -50 °C) and, overall, the rate capability of existing and next-generation battery materials. Heating rates from ~0.5 °C/s to greater than 1 °C/s are demonstrated, quickly enabling delivery of at least ~50% of RT energy and power, as opposed to almost zero without thermal modulation. Following this, the impact of thermal modulation for improved safety and simplified thermal management is explored from a fundamental perspective. The analysis supports the development of heat-resistant batteries that rest safely in a dormant state during non-operation and are “woken up” for operation by thermal modulation for high power. This paradigm shift in battery design and operation simultaneously enables cooling simplification by enlarging the temperature difference driving heat transfer and reducing the rate of heat generation. Motivated by the broad impact of thermal modulation, the SHB design is revisited to discover an opportunity to reduce overall energy consumption by integrating the requisite switching device to share its generated heat with the battery materials for mutual thermal management. Design guidelines are established and implemented to demonstrate a prototype integrated SHB (iSHB). Through experimental and numerical investigation, iSHB heating performance and lifetime comparable to the legacy structure are elucidated. The SHB — and now iSHB — mark the disruption of the more than 200-year-old conventional battery structure, making a passive system active to surrender control of performance to the system designer and make previously unsolvable “and problems” tractable.