Accurate surface control of core–shell structured LiMn0.5Fe0.5PO4@C for improved battery performance†
Manganese-based mixed polyanion cathodes known as LiMn1−xFexPO4 can show much higher energy density as compared to the well-commercialized product of lithium iron phosphate. However, their much lower electronic conductivity has long plagued their further application. Here, by means of a facile solution-based synthesis route, we are able to introduce a uniform and conformal carbon coating layer onto LiMn1−xFexPO4 nanoparticles. The versatility in the synthesis control endows us with the capability of controlling the shell thickness with one nanometer accuracy, offering an effective way to optimize the battery performance through a systematic shell control. Detailed investigation reveals that the carbon nanoshells not only act as good electronic conducting media, but also contribute to the inhibition of the metal (Mn and Fe) dissolution and reduce the exothermic heat released during cycling. The core–shell structured cathode materials show promising potential for their application in lithium ion batteries as revealed by their high charge–discharge capacity, remarkable thermal stability, and excellent cyclability.