Nanocomposites and nanomaterials

High-energy nano-material MoS2 for lithium current sources
Balaban O.V.1, Mitina N.E.2, Larkin M.V.1, Zaichenko A.S.1,2, 
Grygorchak I.I.1 
1 Department of Applied Physics and Nanomaterials Science, Lviv Polytechnic National University. Stepana Bandery Str., 12, Lviv -79013, Ukraine. 
E-mail: oksana.v.balaban@lpnu.ua
2 Department of Organic Chemistry, Lviv Polytechnic National University. Stepana Bandery Str., 12, Lviv -79013, Ukraine.

Materials and technologies that allow us to accumulate and save energy are increasingly in demand in the modern technology development. One of the dominant power storage technologies for both portable electronics and hybrid electric vehicles is Li + intercalation current generation. That is why exactly lithium batteries have a relatively high energy density, high voltage and long lifetime. Cathode materials of lithium intercalated power sources are usually layered materials and molybdenum disulfide is one of them. MoS2 has a structure analogous to that of graphite and is formed by Van der Waals stacking of covalently bonded S-Mo-S layers into a close-packed hexagonal lattice. Such a structure of molybdenum disulfide has guest positions for intercalated lithium. Moreover, after the intercalation process, the host material does not significantly expand in the volume. Being chemically and electronically active, MoS2 has shown great potential for use in electronic devices and in electrocatalysis, sensor and energy storage applications. That is why recently there are a number of publications related to the study of this material.
In our work, we offer various modifications to this material: starting from synthesis method and ending with different coatings. The first thing we discovered is the effect of disordering the structure on the discharge capacity of the studied material. Thus, amorphous molybdenum disulfide has a significantly higher specific capacity, as well as a higher diffusion coefficient of lithium ions, which corresponds to one of the first studies of MoS2.
Another interesting our approach is the synthesis of core-shell nanoparticles where inorganic MoS2 is core and functional polymer is shell. Such nanoscale composite materials are obtained via hydrothermal synthesis of MoS2 nanoparticles with further surface modification of obtained MoS2 nanoparticles by oligoperoxide surfactant, and next grafted radical polymerization from the surface of modified MoS2 nanoparticles.