Mei Cai, the director of battery cell systems research in the Chemical & Materials System Laboratory of GM Research and Development, was honored as Technologist of the Year at the 2021 WOC STEM Conference for her exceptional contributions to science, technology, engineering, and math (STEM).
Mei's remarkable story is inspiring, having come to the United States almost 30 years ago. She was nominated by General Motors (GM) for her outstanding innovations in research and development.
Mei has contributed to developing advanced battery materials, including lithium-ion and advanced battery chemistries, fuel cells, hydrogen and compressed natural gas storage, and battery charging and hydrogen production technologies.
Mei was pivotal in developing GM's Ultium battery chemistry, which will power vehicles like the GMC Hummer EV and the Cadillac Lyriq. GM's Ultium batteries have a unique pouch-style cell design that can be stacked vertically or horizontally inside the battery pack, allowing engineers to optimize battery energy storage and layout for each vehicle design.
Mei and her team have secured 49 patents in this technology area.
Mei is a member of several organizations related to her field, including the Materials Research Society, the Detroit Engineer Association, the Electrochemical Society, and the International Academy of Electrochemical Energy Science.
According to Mark Verbrugge, director of the Chemical & Materials Systems Laboratory at GM Research and Development, Mei is among the few scientists contributing to advancing battery materials discovery and accelerating battery cell manufacturing.
Mei has significantly contributed to advanced energy storage materials, including lithium-ion and battery chemistries, proton-exchange membrane fuel cells, hydrogen and compressed natural gas storage, battery charging, and hydrogen production technologies.
Mei and her team have also developed vital technologies that enable lithium-metal batteries, which could be used in next-generation Ultium cells.
Verbrugge states that GM can use these batteries to increase the onboard energy of its electric vehicles, enabling better range or more energy-dense batteries in lower-cost products.
The rechargeable energy storage system (RESS) for the Chevrolet Bolt EV is a battery pack developed by GM that enables a structurally integrated RESS to sustain vehicle use and abuse conditions.
The compact cooling system improves the energy efficiency of the battery pack but also simplifies the manufacturing process.
The team has also patented various polymers for improved heating, cooling, and liquid leakage control within the battery pack, enabling commercially available vehicles powered by natural gas.
An on-demand NG process allows for the correlation of gaseous fuel and the power demand to maximize NG use.
A three-electrode test cell design and an enabling coated separator are critical components in the cell assembly.
The three-electrode setup allows for independent diagnostics of the positive or negative electrode and precise detection of lithium plating, which calibrates on-vehicle charging control.
This innovative design paves the way for reduced costs for advanced high-energy and high-power EV batteries.
Mei is a member of several prominent organizations, including the Materials Research Society, the Detroit Engineer Association, the Electrochemical Society, and the International Academy of Electrochemical Energy Science.
She grew up in Beijing, which is the capital of the People's Republic of China. Her father was a professor at Tsinghua University. Mei's mother was a medical doctor and was one of two daughters in the family.
Mei considers herself fortunate to have been born into a modern family with an open mind. Mei's parents raised their daughters to believe they could do anything boys can do, even better. Mei's grandparents also played an essential role in her upbringing.
When Mei was very young, her parents took her to live in Changchun, a northeastern city sometimes called the Detroit of China.
Mei's grandfather had earned a chemistry doctorate from the University of Chicago and built a chemistry college from scratch after returning home to Jilin University.
Mei recalls that her grandparents' home was always open to students, and books were everywhere.
Mei was initially drawn to her mother's profession, fascinated by organs in the human body and how her mother worked on healing patients.
However, Mei was also good at math and physics, which was not lost on her mom. Looking back, Mei admits that her parents knew her best.
Mei obtained a bachelor's degree in chemical engineering from Tsinghua University in Beijing.
While studying at Tsinghua, she met her husband, a Ph.D. student on the same campus.
After graduation, Mei worked as a product engineer with a local industrial design institute while her husband continued his studies. Although she was satisfied with her pay and working conditions, Mei had no passion for pursuing an advanced degree.
A few years later, Mei and her husband decided to pursue advanced degrees in the United States.
However, like many other Chinese graduates, they faced challenges when it came to navigating a multi-continental move and finding resources to leave the country.
Fortunately, Mei's grandfather provided financial support, but her husband needed help to complete his Ph.D. before leaving China. The couple worked hard to pay for their airline tickets with the help of their families.
Mei moved to the United States almost 30 years ago as a spouse and had to learn English and prepare for graduate school testing. She experienced several culture shocks but has since fully integrated into American life.
There was a considerable currency difference between the U.S. dollar and the Chinese renminbi, and the couple was living on a $900 scholarship awarded to Mei's husband, which had to cover their rent, groceries, and everything else.
They had no credit cards, and Mei's husband was forced to copy a book from classmates because they couldn't afford it.
After her husband transferred to the University of Michigan, Mei started taking courses for a master's in bioengineering at Wayne State University.
She never gave up on her childhood dream of making artificial organs and put every penny they had into tuition for her first semester.
Although she struggled with speaking English, she found mathematics to be universal.
A professor recommended her for a teaching assistant position in a campus laboratory, and later that year, he recommended her for a summer internship at GM that required a bioengineering background and a driver's license.
Mei's first car was an '82 Buick Regal with over 100,000 miles.
During her two internships at GM, she worked with engineers in engines and fuels and eventually landed a permanent position at the automaker. After that, GM funded her Ph.D. in chemical engineering.
Mei believes that GM does an excellent job in diversity and inclusion, and for the past 25 years, she has worked with people in cross-functional teams, where respect for others and other cultures is essential.
Mei thinks there are many job opportunities for women in the automotive industry, but many might need to be made aware of them. She hopes more women will be educated and informed about these job opportunities.
According to Mei, people should not stay in their comfort zone. Her rules for the road are: Look for new opportunities, set the right expectations, and always prepare yourself because opportunities come and go in life. She advises people to shoot for the Moon; if they miss it, they will still land among the stars.
