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The emerging potassium-ion batteries (PIBs) have been placing stratospheric expectations for realizing grid-scale electrochemical storage of renewable energy. However, the unsatisfactory K-storage of PIB anode materials, especially promising carbonaceous materials, significantly limited the development of PIBs. Here, a molecular design strategy was proposed to realize controllable structure transformation of soft carbon (SC) materials for enhanced K-storage performance. The optimized SC-PCN material delivered a high reversible K-storage capacity of 838 mAh/g at 50 mA/g, outstanding rate capability (213 mAh/g at 1000 mA/g), and excellent long-term cycling performance (301 mAh/g maintained after 300 cycles at 500 mA/g), superior to most previously reported carbon-based PIB anodes materials. Reaction kinetic analysis revealed that the proposed molecular design strategy can achieve the transformation from a surface capacitive-dominated mechanism to a capacitive-diffusion hybrid mechanism for SC-PCN, benefiting from its unique microstructures with highly defective surface generated via the synergistic effect from template removal, N doping, and surface reconstruction. The optimal hybrid K-storage mechanism should be responsible for the excellent K-storage properties of the prepared SC-PCN.

Hydroboration, namely the direct addition of B-H bonds across C=O, C=N, C=C, C≡C and C≡N etc ., unsaturated bonds, is one of important methods for preparing organoborane compounds. Recently, the alkaline earth metal complexes have been widely employed as efficient catalysts for the hydroboration reaction. This article summarizes recent advancements in the alkaline earth metal (especially magnesium) catalyzed hydroboration of unsaturated organic compounds such as aldehydes, ketones, esters, amines, pyridines, nitriles, alkenes, alkynes, carbonates.