LiCoPO4/C nanocomposite with growth controlled by carbonate anions was synthesized via a unique solid-state fusion method. Carbonate anions in the form of H2CO3 or a mixture of H2CO3 +(NH4)2CO3 have been used as a growth inhibiting modifier to produce morphology controlled lithium cobalt phosphate. The presence of cobalt phosphide (Co2P) as a second phase improved the conductivity and electrochemical properties of the parent LiCoPO4. The formation of Co2P is found to be achievable only in an inert atmosphere. Super P® carbon (10wt.%) provided an adherent carbon coating on pristine LiCoPO4 resulting in the LiCoPO4/C composite cathode. This electrode exhibited enhanced electrochemical properties: capacity of 123mAhg−1 with excellent capacity retention of 89% after 30 cycles, and reasonable rate capability of up to 5C rate. The synergistic effect of carbonate anions and formation of Co2P under inert atmosphere has influenced the electrochemical behavior of LiCoPO4/C cathode through controlling the morphology and increasing the conductivity.