A spatial confiment of polysulfides using the metal compound additives having polar surfaces has been considered to be a promising approach to address the insufficient rate capability and cyclability of lithium–sulfur batteries. Herein, we report a more effective approach outperforming this conventional one: a heterogeneous catalysis to promote polysulfide fragmentations. It was revealed using combined computational and experimental approaches that an ultrastrong adsorption of elemental sulfur on TiN surfaces resulted in a spontaenous fragmentation into shorter chains of polysulfides. This heterogeneous catalysis reaction improved the sluggish kinetics of polysulfide reduction because of the chemical disproportionation at the second plateau. A markedly enhanced rate capability was finally obtained, exhibiting a discharge capacity of 700 mAh g–1 at a scan rate of 5C.

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CO2 electroreduction technology is considered an important example of efficient carbon-containing energy sources. Herein, we introduce the metal–support interaction effect with a TiC support for Au/TiC electrocatalysis, which exhibits considerably enhanced activity and selectivity for electroreduction of CO2 to CO while suppressing H2 evolution. With this catalyst, an important electronic effect for CO2 electroreduction was clearly elucidated. Local sp-band charge transfer and d-band shifts play an important role in bonding with both CO and COOH adsorbates. Furthermore, the ideal surface interface between Ti and Au could inevitably maximize the electronic effect, thereby enhancing the catalytic activity of Au/TiC and subsequent CO production.

The sluggish disproportionation of short-chain lithium polysulfides, Li 2 S x , is known to be one of the major causes to limit the rate capability of lithium−sulfur batteries. Herein, we report that tungsten carbide not only affords strong sulfiphilic surface moieties but also provides an efficient catalysis to enhance the polysulfide fragmentation, leading to a drastic improvement in the electrode kinetics. We show that tungsten carbide acts as a superb anchoring material for the long-chain polysulfide and also promotes the dissociation of short-chain polysulfide during the electroreduction process. This leads to a high-rate performance of the composite cathode loaded with tungsten carbide, delivering a markedly enhanced discharge capacity of 780 mA h g −1 at a high current rate of 5 C, when it is applied with a combination of a carbon-coated separator for the polysulfide confinement. Hence, this work presents a new strategic approach for a high-power lithium−sulfur battery.