Sandwich-like Catalyst-Carbon-Catalyst Trilayer Structure as a Compact 2D Host for Highly Stable Lithium-Sulfur Batteries.

Herein, we propose the construction of a sandwich-structured host filled with continuous 2D catalysis-conduction interfaces. This MoN-C-MoN trilayer architecture causes the strong conformal adsorption of S/Li S and its high-efficiency conversion on the two-sided nitride polar surfaces, which are supplied with high-flux electron transfer from the buried carbon interlayer. The 3D self-assembly of these 2D sandwich structures further reinforces the interconnection of conductive and catalytic networks. The maximized exposure of adsorptive/catalytic planes endows the MoN-C@S electrode with excellent cycling stability and high rate performance even under high S loading and low host surface area. The high conductivity of this trilayer texture does not compromise the capacity retention after the S content is increased. Such a job-synergistic mode between catalytic and conductive functions guarantees the homogeneous deposition of S/Li S , and avoids thick and devitalized accumulation (electrode passivation) even after high-rate and long-term cycling.