Ultra-Thin Coating and Three-Dimensional Electrode Structures to Boosted Thick Electrode Lithium-Ion Battery Performance

This paper reports a multiscale controlled three-dimensional (3D) electrode structure to boost the battery performance for thick electrode batteries with LiMn_1.5Ni_0.5O_{4 as} cathode material, which exhibits a high areal capacity (3.5 mAh/cm²) along with a high specific capacity (130 mAh/g). This excellent battery performance is achieved by a new concept of cell electrode fabrication, which simultaneously controls the electrode structure in a multiscale manner to address the key challenges of the material. Particles with ultrathin conformal coating layers are prepared through atomic layer deposition followed by a nanoscale-controlled, thermal diffusion doping. The particles are organized into a macroscale-controlled 3D hybrid-structure. This synergistic control of nano-/macro-structures is a promising concept for enhancing battery performance and its cycle life. The nanoscale coating/doping provides enhanced fundamental properties, including transport and structural properties, while the mesoscale control can provide a better network of the nanostructured elements by decreasing the diffusion path between. Electrochemical tests have shown that the synergistically controlled electrode exhibits the best performance among non-controlled and selectively-controlled samples, in terms of specific capacity, areal capacity, and cycle life.