Li's main research areas are cybersecurity, networking, and mobile computing. He studies trust management policies in wireless networks; cyber-physical systems (such as intelligent transportation systems); the internet of things; and Android mobile devices. Li has published over 70 research papers in peer-reviewed journals and conference proceedings. His research is supported by the U.S. National Institutes of Health (NIH); the U.S. Department of Transportation; and Northrop Grumman Corporation. He is a recipient of the 2019 IEEE Region 1 Technological Innovation (Academic) Award.

Li has served his profession in various ways. A member of both the Association for Computing Machinery (ACM) and the Institute of Electrical and Electronics Engineers (IEEE), he has been a U.S. National Science Foundation panelist since 2015. He has served on organizing committees for conferences including ACM WiSec, IEEE Sarnoff Symposium, IEEE IPCCC, IEEE MDM, IEEE DySPAN, and IEEE CyberSciTech. He also served on program committees for well-known conferences IEEE INFOCOM, IEEE GLOBECOM, IEEE ICC, IEEE WCNC, IEEE IPCCC, IEEE VTC, IEEE MDM, and others. In addition, Li has reviewed papers for many top-tier peer-reviewed journals (IEEE Transactions on Parallel and Distributed Systems, IEEE Transactions on Wireless Communications, IEEE Transactions on Dependable and Secure Computing, IEEE Internet of Things, and IEEE Transactions on Information Forensics and Security, among others).