Synthesis

Cathode materials for Li-S batteries

Metal oxide nanoparticles and free-standing porous carbon monolith can be synthesized through polymer assisted colloidal approaches. The well-defined nanostructures can be applied as cathode materials in Li-S batteries with excellent electrochemical performance. For example, Magnéli phase Ti4O7 particles with interconnected-pores structure can be synthesized by using porous PS-P2VP particles as template.[1] They can provide mesopores for physical confinement and polar surface for chemically bonding with polysulfides to suppress their dissolution. Moreover, light-weight and mechanically stable carbon monoliths have been prepared from a hydrothermal method. This binder-free monolith have been used as model cathode material for a multidimensional operando analysis.

[1] S. Mei, C.J. Jafta, I. Lauermann, Q. Ran, M. Kärgell, M. Ballauff, Y. Lu, Advanced Functional Materials 2017, 27, 1701176 .

SEM images of the porous Ti₄O₇ particles as well as the carbon-coated Ti₄O₇ particles (top). Adsorption of polysulfides by Ti₄O₇ nano particles (bottom, left). Rate capabilities of the Ti₄O₇ based cathode and the carbon-coated Ti₄O₇ based cathode at different current rates (bottom, right).