Alternating current heating techniques for lithium-ion batteries in electric vehicles: Recent advances and perspectives

The significant decrease in battery performance at low temperatures is one of the critical challenges that electric vehicles (EVs) face, thereby affecting the penetration rate in cold regions. Alternating current (AC) heating has attracted widespread attention due to its low energy consumption and uniform heating advantages. This paper introduces the recent advances in AC heating from the perspective of practical EV applications. First, the performance degradation of EVs in low-temperature environments is introduced briefly. The concept of AC heating and its research methods are provided. Then, the effects of various AC heating methods on battery heating performance are reviewed. Based on existing studies, the main factors that affect AC heating performance are analyzed. Moreover, various heating circuits based on EVs are categorized, and their cost, size, complexity, efficiency, reliability, and heating rate are elaborated and compared. The evolution of AC heaters is presented, and the heaters used in brand vehicles are sorted out. Finally, the perspectives and challenges of AC heating are discussed. This paper can guide the selection of heater implementation methods and the optimization of heating effects for future EV applications.