Not everyone uses used tea leaves to make supercapacitors. The authors of this study are among the people who do:
“Eco-Friendly and High Performance Supercapacitors for Elevated Temperature Applications Using Recycled Tea Leaves,” Sanket Bhoyate, Charith K. Ranaweera, Chunyang Zhang, Tucker Morey, Megan Hyatt, Pawan K. Kahol, Madhav Ghimir, Sanjay R. Mishra, and Ram K. Gupta, Global Challenges, vol. 1, no. 8, November 16, 2017, article 1700063.