To ensure sustainable hydrogen production by water electrolysis, robust, earth-abundant, and high-efficient electrocatalysts are required. Constructing a hybrid system could lead to further improvement in electrocatal...
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To ensure sustainable hydrogen production by water electrolysis, robust, earth-abundant, and high-efficient electrocatalysts are required. Constructing a hybrid system could lead to further improvement in electrocatalytic activity. Interface engineering in composite catalysts is thus critical to determine the performance, and the phase-junction interface should improve the catalytic activity. Here, we show that nickel diphosphide phase junction ( c -NiP 2 / m -NiP 2 ) is an effective electrocatalyst for hydrogen production in alkaline media. The overpotential (at 10 mA cm −2 ) for NiP 2 -650 ( c / m ) in alkaline media could be significantly reduced by 26 % and 96 % compared with c -NiP 2 and m -NiP 2 , respectively. The enhancement of catalytic activity should be attributed to the strong water dissociation ability and the rearrangement of electrons around the phase junction, which markedly improved the Volmer step and benefited the reduction process of adsorbed protons.
Without excess Li, anode-free Li-metal batteries (AFLMBs) have been proposed as the most likely solution to realizing highly-safe and cost-effective Li-metal batteries. Nevertheless, short cyclic life puzzles conventi...
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Without excess Li, anode-free Li-metal batteries (AFLMBs) have been proposed as the most likely solution to realizing highly-safe and cost-effective Li-metal batteries. Nevertheless, short cyclic life puzzles conventional AFLMBs due to anodic dead Li accumulation with a local current concentration induced by irreversible electrolyte depletion, insufficient active Li reservoir and slow Li + transfer at the solid electrolyte interphase (SEI). Herein, SrI 2 is introduced into carbon paper (CP) current collector to effectively suppress dead Li through synergistic mechanisms including reversible I − /I 3 − redox reaction to reactivate dead Li, dielectric SEI surface with SrF 2 and LiF to prevent electrolyte decomposition and highly ionic conductive (3.488 mS cm −1 ) inner layer of SEI with abundant LiI to enable efficient Li + transfer inside. With the SrI 2 -modified current collector, the NCM532/CP cell delivers unprecedented cyclic performances with a capacity of 129.2 mAh g −1 after 200 cycles.
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