While grain conductivity of lithium titanium phosphate materials (LTP) is high, the total conductivity is relatively low due to high resistant grain boundary phase. The work demonstrates that this resistance can be substantially reduced by helps of LiI. For this purpose a series of the LTP-LiI composites were formed employing mechanical ball-milling. X-ray diffractometry, thermogravimetry, impedance spectroscopy, scanning electron microscopy and density methods were used to characterize obtained materials. A maximum enhancement of total ionic conductivity at 30 degrees C was recorded for the LTP containing 8 wt.% of LiI (7.3 x 10(-6) S.cm(-1) comparing to 1.5 x 10(-8) S.cm(-1) for pure LTP). (C) 2016 Elsevier B.V. All rights reserved.