Membrane capacitive deionization (MCDI),a promising technology in desalination community,has attracted enormous attentions because it can effectively achieve the desalination with low cost and low driving energy.In this paper,batch mode experiments were carried out to evaluate the performance of MCDI by investigating its charge efficiency.The results show that the charge efficiency in MCDI is a function of both cell voltage and solution conductivity.Specifically,it is found that the charge efficiency is proportional to cell voltage while inversely to solution conductivity.The maximum charge efficiency (0.55) in MCDI is far less than 1,indicating the high transient resistivity between membrane and carbon electrodes.