This paper reviews recent advancements and optimizations in cell-balancing techniques for lithium-ion batteries used in electric vehicles (EVs). The review covers the operating principles and optimized utilization of electrical components in various cell-balancing methods. Key topics include: 1. **Closed-Loop Switched-Capacitor Structure**: This method uses PI control to address issues with traditional cell-balancing approaches, providing efficient voltage equalization between cells. 2. **Parallel Resonant Switched-Capacitor Equaliser**: This technique improves efficiency by reducing switching frequency and limiting inrush current, but it is limited to balancing adjacent cells. 3. **Single Inductor Bidirectional Cell Balancing**: This method uses a single inductor with multiple channels to achieve fast balancing speed and flexibility in energy transfer modes. 4. **Coupled Inductor Cell Balancing**: This approach minimizes power loss and balancing time by transferring energy between cells and the battery pack using two inductors. 5. **Single Inductor Cell Balancing with an Auxiliary Battery**: This topology uses an auxiliary battery to supply or draw energy during the balancing process, enhancing balancing efficiency. 6. **Double-Layer Inductive Equalisation Circuit**: This method combines layering concepts and inductance balancing to achieve fast cell balancing. 7. **Advanced Switched-Capacitor Equaliser Circuit**: This circuit integrates Cuk and buck-boost converters to minimize the number of switches and achieve fast balancing. 8. **Push-Pull Converter-Based Cell-Balancing Circuit**: This method uses relays instead of MOSFETs to reduce costs and simplify control implementation. 9. **Dual DC-DC Converter-Based Cell Balancing with an Auxiliary Battery**: This topology uses both voltage and SOC-based control algorithms to improve balancing efficiency. 10. **Single Resonant Converter Balancing Circuit**: This active balancing circuit optimizes cell-to-cell balancing by reducing the number of switches and achieving soft switching. The paper concludes by summarizing the recent advancements and optimizations in cell-balancing techniques, highlighting the trade-offs between efficiency, balancing speed, and complexity. The review provides a comprehensive overview of the latest developments in cell-balancing methods, emphasizing the importance of balancing for the performance, safety, and longevity of lithium-ion battery systems in EVs.This paper reviews recent advancements and optimizations in cell-balancing techniques for lithium-ion batteries used in electric vehicles (EVs). The review covers the operating principles and optimized utilization of electrical components in various cell-balancing methods. Key topics include: 1. **Closed-Loop Switched-Capacitor Structure**: This method uses PI control to address issues with traditional cell-balancing approaches, providing efficient voltage equalization between cells. 2. **Parallel Resonant Switched-Capacitor Equaliser**: This technique improves efficiency by reducing switching frequency and limiting inrush current, but it is limited to balancing adjacent cells. 3. **Single Inductor Bidirectional Cell Balancing**: This method uses a single inductor with multiple channels to achieve fast balancing speed and flexibility in energy transfer modes. 4. **Coupled Inductor Cell Balancing**: This approach minimizes power loss and balancing time by transferring energy between cells and the battery pack using two inductors. 5. **Single Inductor Cell Balancing with an Auxiliary Battery**: This topology uses an auxiliary battery to supply or draw energy during the balancing process, enhancing balancing efficiency. 6. **Double-Layer Inductive Equalisation Circuit**: This method combines layering concepts and inductance balancing to achieve fast cell balancing. 7. **Advanced Switched-Capacitor Equaliser Circuit**: This circuit integrates Cuk and buck-boost converters to minimize the number of switches and achieve fast balancing. 8. **Push-Pull Converter-Based Cell-Balancing Circuit**: This method uses relays instead of MOSFETs to reduce costs and simplify control implementation. 9. **Dual DC-DC Converter-Based Cell Balancing with an Auxiliary Battery**: This topology uses both voltage and SOC-based control algorithms to improve balancing efficiency. 10. **Single Resonant Converter Balancing Circuit**: This active balancing circuit optimizes cell-to-cell balancing by reducing the number of switches and achieving soft switching. The paper concludes by summarizing the recent advancements and optimizations in cell-balancing techniques, highlighting the trade-offs between efficiency, balancing speed, and complexity. The review provides a comprehensive overview of the latest developments in cell-balancing methods, emphasizing the importance of balancing for the performance, safety, and longevity of lithium-ion battery systems in EVs.