A　novel　LSB-doped　GDC　(LGDC)　electrolyte　has　been　developed.　Ce0.8Gd0.2O1.9　(GDC)　and　Bi0.775La0.225O1.5　(LSB)　have　been　synthesized　by　a　citric　acid-nitrate　sol-gel　method　and　a　conventional　solid-state　reaction　method,　respectively.　A　series　of　LGDC　are　fabricated　by　mixing　nanosized　GDC　powder　with　1,　3,　10,　15,　and　20 wt%　of　LSB　at　the　sintering　temperature　of　1300 °C.　The　X-ray　diffraction　results　indicate　that　all　the　LGDC　electrolytes　are　single　phase　without　any　other　impurity　phases　exist.　The　relative　density　of　LGDC　electrolytes　firstly　increases　and　then　decreases　when　increasing　the　proportion　of　LSB.　The　ionic　conductivity　of　3LGDC　(1.47　×　10−2 S cm−1)　is　~　75%　higher　than　that　of　GDC　(8.38　×　10−3 S cm−1)　at　600 °C.　The　maximum　power　density　of　the　single　cells　based　on　10LGDC　co-fired　at　1300 °C　can　reach　655 mW cm−2　at　700 °C.　This　maximum　power　density　is　~　110%　higher　than　that　of　the　GDC-based　cell.　The　introduction　of　LSB　significantly　improve　the　open　cell　voltages　(OCVs)　of　the　single　cells.　Moreover,　the　long-term　stability　is　maintained　up　to　more　than　100 h,　demonstrating　high　stability　of　the　LGDC　electrolytes.　Hence,　we　trust　that　this　LGDC　electrolytes　can　be　chosen　to　a　promising　electrolyte　for　high-performance　IT-SOFCs.　©　2018,　Springer-Verlag　GmbH　Germany,　part　of　Springer　Nature.