锂离子电池能量效率的研究

Research of Li-ion battery's energy efficiency

现有能量效率算法只能反映充放电一个循环的效率,它将充电能量损失与放电能量损失耦合在一起,不适用于充电和放电过程分离的场合。基于锂离子电池OCV与SOC之间存在一一对应关系,提出了电池理论能量的概念,将电池的能量效率细分为充电能量效率、放电能量效率以及充放电能量效率,提出了适用于这类电池的能量效率算法,并通过实验验证了该算法的可行性。

The existing algorithm of battery＇s energy efficiency can only reflect the energy efficiency of one cycle of charging and discharging, which couples the loss of charging and discharging progress,and it can＇t be applied in the condition of only charging or discharging progress. A new algorithm of Li-ion battery＇s energy efficiency was proposed after suggesting concept of Li-ion battery＇s ideal energy, for the open circuit voltage （OCV） and state of charge （SOC） sharing a one-to-one mapping. For different applications, the energy efficiency was classified to three types, namely, the charging energy efficiency, the discharging energy efficiency and the charging and discharging energy efficiency. The corresponding calculation formulas of each definition were also proposed. Thereby, different experiments were designed to study the variations of the three kinds of energy efficiency. The results indicate that within a certain range, all the efficiency algorithm above show certain regularity under different affecting factors.