ELECTRICAL PROPERTY AND SINTERABILITY OF LITI2(PO4)3 MIXED WITH LITHIUM SALT (LI3PO4 OR LI3BO3)

A lithium salt (Li3PO4 or Li3BO3) was added to LiTi2(PO4)3 to obtain a dense pellet of the phosphate. The porosity of the sintered pellets decreased and the conductivity was enhanced by the utilization of a binder. A maximum conductivity of 3.0 x 10(-4) S.cm-1 at 298 K was obtained for a sample of LiTi2(PO4)3-0.2Li3BO3. The activation energy for the lithium migration at grain boundaries was decreased by the addition of lithium salt. The reason for the conductivity enhancement was attributed to a decrease in the activation energy for the lithium migration at the grain boundary and an increase in the contact area between grains. The conductivity of the bulk component was also increased by the enhancement of Li+-ion migration at grain boundaries.