A novel structure of a carbon-coated LiMnPO4 microcluster through emulsion-based self-assembly has been fabricated to yield a high-performance battery cathode. In this rational design, nanosized LiMnPO4 plates are assembled into microclusters to achieve a dense packing and robust interparticle contact. In addition, the conductive carbon framework wrapping around these clusters functions as a fast electron highway, ensuring the high utilization of the active materials. The designed structure demonstrates enhanced specific capacity and cycling stability in lithium-ion batteries, delivering a discharge capacity of 120 mAh g-1 after 200 cycles at 0.2 C. It also shows a superior rate capability with discharge capacities of 139.7 mAh g-1 at 0.05 C, 131.7 mAh g-1 at 0.1 C, and 99.2 mAh g-1 at 1 C at room temperature.