In　this　paper,　a　ceramic　sealant　(CaB2O4)　is　developed　for　the　self-healing　design　of　solid　oxide　fuel　cells　(SOFCs).　The　interface　between　this　ceramic　sealant　and　the　anode-supported　electrolyte,　e.g.,　8　mole%　yttria-stabilized　zirconia　(8YSZ),　remains　intact　after　sixty　thermal　cycles　from　800　degrees　C　to　room　temperature.　An　in　situ　observation　verifies　that　the　micro-indentation　on　the　surface　of　this　material　can　be　healed　when　heating　from　room　temperature　to　920　degrees　C　at　a　heating　rate　of　40　degrees　C　min(-1).　In　addition,　the　weight　loss　of　CaB2O4,　held　at　850　degrees　C　in　air　for　28　days,　decreases　from　3.26　+/-　0.73　for　sealed　species　to　0.81　+/-　0.04　mg　cm(-2)　for　fully　crystallized　species;　meanwhile,　the　weight　loss　of　CaB2O4,　held　at　850　degrees　C　in　wet　forming　gas　(30　vol%　water　vapor)　for　28　days,　decreases　from　14.80　+/-　1.83　for　sealed　species　to　6.36　+/-　0.64　mg　cm(-2)　for　fully　crystallized　species.　Combining　with　the　good　mechanical　stability　and　thermal-stability,　this　self-healing　ceramic　sealant　provides　promising　solution　for　the　sealing　challenge　of　planar　SOFCs.　(C)　2012　Elsevier　B.V.　All　rights　reserved.