Performance evaluation of solid-state lithium batteries for UAV applications: Endurance, temperature adaptability, and self-discharge

With the rapidly growing demand for power sources in unmanned aerial vehicles (UAVs), enhancing lithium battery performance has become a key pathway for optimizing UAV power systems. Among emerging technologies, solid-state lithium batteries (SSLBs), which replace conventional liquid electrolytes with solid-state electrolytes, have attracted considerable attention due to their potential performance advantages. To systematically evaluate the suitability of SSLBs as UAV power sources, this study comparatively investigates the endurance performance, temperature adaptability, and standby self-discharge characteristics of SSLBs, lithium polymer batteries (LiPos), and lithium iron phosphate batteries (LFPBs). Endurance analysis shows that, benefiting from their high energy density, SSLBs achieve a cruising endurance of 6.973 h and a theoretical maximum endurance of 15.567 h, outperforming LiPos and LFPBs. To assess environmental robustness, an eight-level temperature gradient experiment is conducted, and the dynamic terminal voltage responses of the three battery systems are analyzed. Results indicate that LiPo exhibits superior temperature adaptability, maintaining an average voltage deviation of approximately 11% at −15 °C, whereas SSLB and LFPB show larger deviations of around 20%. Furthermore, the open-circuit voltage (OCV) decay method is employed to quantify charge retention during standby. Under room-temperature, SSLB and LiPo demonstrate similarly self-discharge rates of 0.41% and 0.4%, respectively, while LFPB exhibits a lower self-discharge rate of 0.14%. This study provides critical experimental data and theoretical references for the scientific selection of UAV power batteries, the expansion of application scenarios, and the targeted performance optimization of SSLB.