Many battery materials are synthesized via calcination of precursor particle powders with a lithium source. The precursor particles frequently are made via coprecipitation reactions, and a number of combinations of coprecipitation agents have been demonstrated previously. Detailed control over the morphology of precursor particles and the resulting final electrode materials would be highly desirable, but currently detailed understanding of the impact of synthesis conditions on precursor morphology are lacking. Herein, tunable monodisperse MnCO3 particles for Li-ion battery precursors of varying size and shape were synthesized through batch coprecipitation. The effect of solution chemistry on final particle morphology was confirmed via scanning electron microscopy and considered in the context of solution equilibrium calculations and nucleation and growth of precipitate crystals. The tunability of MnCO3 particle morphology with reagent concentration was demonstrated with transitions from rhombohedra to cubes to spheres to smaller spheres with regards to overall secondary particle structures. Other experimental factors were also examined to further understand the processes resulting in the transitions in MnCO3 morphology. Precursor particles were calcined to form LiMn2O4 to verify the ability to maintain the tunable morphology in the final battery materials and to confirm suitability for battery cathodes. (C) 2015 Elsevier B.V. All rights reserved.