A　barrier　that　limits　the　development　of　the　conventional　cation-exchange　membrane　direct　liquid　fuel　cells　(CEM-DLFCs)　is　that　the　CEM-DLFCs　need　additional　base　to　offer　both　alkaline　environment　and　charge　carriers.　Herein,　we　propose　a　Na+-conducting　direct　formate　fuel　cell　(Na-DFFC)　that　is　operated　in　the　absence　of　added　base.　A　proof-of-concept　Na-DFFC　yields　a　peak　power　density　of　33　mW　cm(-2)　at　60　degrees　C,　mainly　because　the　hydrolysis　of　sodium　formate　provides　enough　OH-　and　Na+　ions,　proving　the　conceptual　feasibility.　Moreover,　contrary　to　the　conventional　chlor-alkali　process,　this　Na-DFFC　enables　to　generate　electricity　and　produce　NaOH　simultaneously　without　polluting　the　environment.　The　Na-DFFC　runs　stably　during　13　hours　of　continuous　operation　at　a　constant　current　of　10　mA,　along　with　a　theoretical　production　of　195　mg　NaOH.　This　work　presents　a　new　type　of　electrochemical　conversion　device　that　possesses　a　wide　range　of　potential　applications.