This chapter delves into the intricate degradation mechanisms of lithium-ion batteries (LIBs) under low-temperature conditions, emphasizing the effects of low-temperature charging and alternating current (AC) heating. At low temperatures, LIBs exhibit significant performance degradation, characterized by decreased capacity, slower charging rates, and increased likelihood of lithium plating. The primary factors contributing to this degradation include elevated solid–liquid interface impedance, charge transfer impedance, solid-phase diffusion impedance, and the formation of lithium plating on the graphite anode. Lithium plating, a detrimental side reaction during charging, not only leads to irreversible capacity loss but also poses safety risks by potentially causing internal short circuits and thermal runaway. This chapter first investigates the aging mechanism of LIBs in charge/discharge cycles at low temperatures. Experimental results reveal that the degradation is more pronounced at high charging rates and low temperatures, with lithium plating being the dominant mechanism driving capacity fade. The study also investigates the effectiveness of AC heating methods in mitigating low-temperature effects. AC heating demonstrates uniform temperature distribution and minimal battery degradation after extensive cycling, making it a promising strategy for enhancing LIB performance in cold environments. The findings underscore the importance of optimizing battery management strategies and material designs to improve the low-temperature performance of LIBs. These insights are particularly valuable for the development of energy storage technologies in electric vehicles (EVs) and other applications where reliable operation under varying environmental conditions is crucial. Overall, this chapter summarizes the low-temperature degradation mechanism of LIBs, which is an important guide for the design of future low-temperature batteries and the development of battery management system (BMS).