Nickel embedded porous macrocellular carbon derived from popcorn as sulfur host for high-performance lithium-sulfur batteries

Due to the demands for high performance and ecological and economical alternatives to conventional lithium-ion batteries (LiBs), the development of lithium-sulfur (Li-S) batteries with remarkably higher theoretical capacity (1675 mA h g−1) has become one of the extensive research focus directions worldwide. However, poor conductivity of sulfur, critical cyclability problems due to shuttle of polysulfides as intermediate products of the cathodic reaction, and large volume variation of the sulfur composite cathode upon operation are the major bottlenecks impeding the implementation of the next-generation Li-S batteries. In this work, a unique three-dimensional (3D) interconnected macrocellular porous carbon (PC) architecture decorated with metal Ni nanoparticles was synthesized by a simple and facile strategy. The as-fabricated Ni/PC composite combines the merits of conducting carbon skeleton and highly adsorptive abilities of Ni, which resulted in efficient trapping of lithium polysulfides (LiPSs) and their fast conversion in the electrochemical process. Owing to these synergistic advantageous features, the composite exhibited good cycling stability (512.3 mA h g−1 after 1000 cycles at 1 C with an extremely low capacity fading rate 0.03 % per cycle), and superior rate capability (747.5 mA h g−1 at 2 C). Accordingly, such Ni nanoparticles embedded in a renewable puffed corn-derived carbon prepared via a simple and effective route represent a promising active type of sulfur host matrix to fabricate high-performance Li-S batteries.