She checked out apples, rice husks and bitter gourd. But the Chinese eggplant became an early front runner.
"It's very porous, which suggests a high surface area to volume ratio," she said.
By using eggplant, or brinjal, to create more durable, cheaper and environmentally friendly batteries, Shannon Lee has made Singapore history. The 17-year-old is the first Singaporean to win a top prize at the annual Intel International Science and Engineering Fair, sometimes called the Olympics of the science calendar.
The National Junior College (NJC) Year 6 student beat close to 1,800 students from around the world this month. "Her research may significantly improve batteries of the future and may have a wide range of applications, such as improving the energy performance of hybrid vehicles," read her award's citation.
"My jaw dropped," she told The Straits Times last week. "It was my first time at the fair."
The fair is the world's largest pre-college science competition. It is organised by the non-profit, US-based Society for Science and the Public and is supported by computer giant Intel.
Students from more than 70 countries competed in this year's edition, held earlier this month in Los Angeles in the United States.
Shannon's project won her three awards, including US$58,000 (S$72,700) for higher education and the Intel Foundation Young Scientist Award, the fair's second-most prestigious honour.
The top prize, the Gordon E. Moore Award, went to US student Nathan Han, 15, for developing a computer programme that studies gene mutations linked to breast and ovarian cancer.