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Lithium (Li) metal anodes are demanded by high-energy Li batteries because Li has the highest capacity and low electrode potential. However, Li metal anodes usually show poor cyclability and unsafe deposition at anode/separator interfaces, which may increase the risk of short circuits. In this work, we fabricate a sandwiched structure of reduced graphene oxides (rGO) with silicon (Si) quantum dots (QDs) as the inducing agents between rGO layers. Because of the lithiophilicity of Si QDs, Li growth is favorably guided away from the unsafe anode/separator interface towards the interlayer positions, significantly improving the cyclability and safety of the Si-QDssandwiched rGO anode. The uniformly-distributed Si QDs and layered electrode structure can regulate Li plating/stripping to avoid the superficial Li growth and reduce the accumulation of solid electrolyte interphase. The growth-guiding strategy using the sandwiched structure provides a new approach to fabricating high energy Li-based battery anodes.

Manganese oxide (MnO 2 ) is a commonly used vulcanizing agent, which can convert polysulfide oligomers with reactive terminal mercaptans into polymeric networks. Herein, an elegant approach for the fast and facile curing behavior of polysulfide rubbers was disclosed under visible-light irradiation. Photocatalytic disulfide bond coupling of mercaptan end groups can be achieved on MnO 2 in the presence of visible-light irradiation. More importantly, compared with pristine MnO 2 , surface-reduced MnO 2 (R-MnO 2 ) with abundant Mn 3+ sites and oxygen vacancies exhibited superior vulcanizing performance. Theoretical simulation uncovers that R-MnO 2 can facilitate electron transfer due to a narrowed energy band gap and reduce the energy barriers required for photocatalytic disulfide bond formation. This work opens up the potential of using visible light together with surface modification to tune the vulcanizing process and the properties of polysulfide rubbers.

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