Electrostatic self-assembly of LiFePO4 cathodes on a three-dimensional substrate for lithium ion batteries

In this work, the electrostatic self-assembly of LiFePO4 particles coated with polyelectrolytes on a three-dimensional carbon substrate is described. This new fabrication method allows precise control of ionic and electronic conduction pathways as well as the interfaces between the different electrode components, thus enabling new strategies for tailored electrode designs. Further, it is shown that the polyelectrolytes used to build up the electrode by electrostatic self-assembly can be converted into a conductive matrix by a simple carbonization step. This leads to a firmly adhering carbon film on the surface of LiFePCO4, which further improves electron transport. The three-dimensional composite cathode exhibits a high specific capacity even at high current rates as well as a long cycle life. The excellent electrochemical performance can be attributed to the improved three-dimensional structure of the electrode as well as to the obtained intrinsic carbon coating of LiFePCO4 particles. (C) 2018 Elsevier Ltd. All rights reserved.