Solid-state electrolytes (SSEs) show potential in addressing the safety issues of liquid batteries,b ut the poor interface contact between them and the electrodes hinders practical applications.H ere,c oordination chemistry of nitrile groups based on succinonitrile (SCN) and polyacrylonitrile (PAN) is studied on the surface of Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 (LLZTO) SSE to build the chemical bonded electrolyte/ electrode interfaces.T he coordination of the nitrile group and LLZTOi sc larified. Ad eformable PAN-modifying SCN electrolyte (PSE) interphase with stable ionic conductivity (10 À4 Scm À1 )and high lithium-ion transference number (0.66) is fabricated on the surface of LLZTOelectrolyte based on the coordination competition of nitrile groups.O nce applied to SSBs,itendows lowinterface resistance and strong bonding for the electrolyte/electrode interfaces so that the initial Coulomb efficiency reaches 95.6 %a nd the capacity remains 99 %a fter 250 cycles at 25 8 8C.