Formation of a glue-nanofiller layer between grains, consisting of a middle-temperature spinel-like LixCoO2 phase, reinforces the strength of the incoherent interfacial binding between anisotropically oriented grains by enhancing the face-to-face adhesion strength. The cathode treated with the glue-layer exhibits steady cycling performance at both room-temperature and 60 degrees C. These results represent a step forward in advanced lithium-ion batteries via simple cathode coating.