With the development and large-scale application of 5G, artificial intelligence (AI), Internet of Things (IoT) and other software and hardware technologies, mobile devices vary in forms,  application scenarios and quantities, which facilitate consumers’ work and daily life. 

There are more than 2 billion smart phones and IoT devices produced globally, according to the  market data. A lot of electronic waste has already been made by mobile devices themselves and  their chargers, because people tend to keep pace with the latest products and producers adopt  different charging protocols. Moreover, when mobile devices keep gaining new functions, they turn  out to consume more energy and take longer time to recharge. In that case, the energy efficiency of  mobile devices directly affect the utilization of environmental resources.