Research On The Fast Charging Method Of Lithium Battery

In recent years,lithium battery has gradually replaced the traditional rechargeable battery because of its low self-discharge efficiency,large battery capacity ratio and high safety,and became a widely used battery.With the increasing functions of portable devices,the energy consumption of devices increases,and higher requirements are put forward for the charging speed of lithium batteries.Charging method has a great influence on charging speed and life of lithium battery.With the continuous development of science and technology,the charging speed of existing charging methods couldnot meet People's Daily needs gradually,and improving the charging speed of batteries had became the focus of current research on lithium battery charging.After the traditional constant-current and constant-voltage charging methods are widely used,in order to improved the lithium batteries charging efficiency,a variety of quick charging methods had been proposed in recent years,such as pulse charging and intermittent charging.Although these quick charging methods greatly improved the charging speed of lithium battery,there is still some polarization phenomenon in the charging process,and also a gap between the charging current and the lithium battery's maximum acceptable charging current.Aimed at these problems in the existing charging methods,the main reasearch contents as follows:(1)Conducted PNGV circuit analysis and parameter identification experiments for different types and capacities of lithium batteries,build circuit model for lithium batteries.(2)In view of the influence of current,voltage and temperature on the estimation accuracy of lithium battery SOC estimation,adaptive kalman filter algorithm was adopted to estimate the SOC of circuit model of lithium battery,then build Simulink module to verify the algorithm.(3)In view of the existing charging method the problem of charging speed,algorithm of NSGA-? is used to optimize the charging method.To get the battery parameters as initial value of genetic algorithm,Matlab is used to simulate the existing charging method.Based on STM32,a charging system had been build to validated the optimized charging method.The result improved the lithium battery charging speed,proved the feasibility of the optimized charging method.