[Ca24Al28O64](4+)　(4e(-))　eletride,　as　the　first　room-temperature　stable　inorganic　electride,　has　attracted　intensive　attention　because　of　its　fascinating　chemical,　electrical,　optical,　and　magnetic　properties.　However,　it　usually　needs　synthesizing　through　a　complicated　multistep　process　involving　high　temperature　(e.g.,　1350　degrees　C),　severe　reduction　(e.g.,　700-1300　C　for　up　to　240　h　in　Ca　or　Ti　metal　vapor　atmosphere)　and　post-purification.　Owing　to　the　H2O　sensitivity　of　mayenite,　the　post-purification　is　quite　troublesome　once　impurities　are　introduced.　High-density,　loosely　bound　encaged　electrons　with　a　low　work　function　make　it　promise　to　possess　practical　applications.　Therefore　the　facile　method　of　massively　producing　the　high-quality　C12A7:e-　with　high　Ne　is　extremely　desired.　In　this　work,　C12A7:e-　bulks　are　for　the　first　time　synthesized　by　simple　spark　plasma　sintering　process　directly　from　a　mixture　of　C12A7,　CA　and　Ca　powders　under　milder　conditions　(e.g.,　sintered　at　1070　C　for　10　min　in　a　vacuum).　The　obtained　electride,　which　exhibits　a　relative　density　of　99%,　an　electron　concentration　of　2.3x　1021　cm-3　and　an　obvious　absorption　peak　at　2.5　eV,　is　obtained　via　SPS　process　at　1100　C　for　10　min.　Electronic　structure　is　also　investigated　by　electron　paramagnetic　resonance.　The　occurrence　of　Dysonian　characteristic,　a　typical　feature　of　good　electronic　conductors,　strongly　suggests　that　the　electrons　are　trapped　in　mayenite　cavities.　Furthermore,　the　obtained　C12A7:e-　exhibits　good　sinterabilty　on　a　crystal　scale　of　5-40　um.　Thermionic　emission　test　results　show　that　the　thermionic　emission　begins　to　occur　at　700　K　and　a　large　current　density　of　1.75　A/cm2　is　obtained　in　the　electron　thermal　emission　from　a　flat　surface　of　the　polycrystalline　C12A7:e-　with　an　effective　work　function　of　2.09　eV　for　a　temperature　of　1373　K　with　an　applied　electric　field　of　35000　V/cm　in　a　vacuum.　Owing　to　no　external　reductant　is　needed,　this　developed　route　exhibits　notable　superiority　over　the　conventional　reduction　method　for　phase-pure　C12A7:e-.　Therefore,　these　results　not　only　suggest　a　novel　precursor　for　fabricating　mayenite　electride　but　also　make　it　possible　to　produce　efficiently　the　electride　in　large　volume.