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Organic compounds exhibit great potential as sustainable, tailorable, and environmentally friendly electrode materials for rechargeable batteries. However, the intrinsic defects of organic electrodes, including solubility, low ionic conductivity, and restricted electroactivity sites, will inevitably decrease the cycling life and capacity. We herein designed and prepared nanostructured porous polymers (NPP) with a simple one-pot method to overcome the above defects. Theoretical calculations and experimental results demonstrate that the as-synthesized NPP exhibited low volume expansion, molecular-structural distortion, and a gradual function activation process during cycling, thus exhibiting superior, high, and durable lithium storage. The gradual molecular distortion during the lithium storage processes provides more redox-active sites for Li storage, increasing the Li-storage capacity. Ex situ spectrum studies reveal the redox reaction mechanism of Li storage and demonstrate a gradual activation process during the repeated charging/discharging until the full storage of 18 Li ions is achieved. Additionally, a real-time observation on the NPP anode by in situ transmission electron microscope reveals a slight volume expansion during the repeating lithiation and delithiation processes, ensuring its structural integrity during cycling. This quantitative work for high-durability lithium storage could be of immediate benefit for designing organic electrode materials.

Intermetallic compounds, featuring atomically ordered structures, have emerged as a class of promising electrocatalysts for fuel cells. However, it remains a formidable challenge to controllably synthesize Pt-based intermetallics during the essential high-temperature annealing process as well as stabilize the nanoparticles (NPs) during the electrocatalytic process. Herein, we demonstrated a Ketjen black supported intermetallic Pt 3 Ti nanocatalyst coupled with amorphous TiO x species (Pt 3 Ti-TiO x /KB). The TiO x can not only confine Pt 3 Ti NPs during the synthesis and electrocatalytic process by a strong metal-oxide interaction but also promote the water dissociation for generating more OH species, thus facilitating the conversion of CO ad . The Pt 3 Ti-TiO x /KB showed a significantly enhanced mass activity (2.15 A mg Pt -1 ) for the methanol oxidation reaction, compared with Pt 3 Ti/KB and Pt/C, and presented an impressively high mass activity retention (∼71%) after the durability test. This work provides an effective strategy of coupling Pt-based intermetallics with functional oxides for developing highly performed electrocatalysts.

The development of the electrocatalyst-integrated electrodes with HER/OER bifunctional activity is desirable to reduce the cost and simplify the system of the practical water electrolyzers. Herein, we construct a new type of Ni 3 Fe 1- x Cr x (0 ≤ x < 0.3) intermetallic integrated electrodes for overall water splitting via an ultrafast carbothermal shock method. The obtained Ni 3 Fe 0.9 Cr 0.1 /CACC electrode exhibits the optimum performance among all developed electrocatalyst electrodes in this work, and the overpotential is merely 239 mV for OER and 128 mV for HER at 10 mA cm -2 . In addition, the Ni 3 Fe 0.9 Cr 0.1 /CACC electrode shows excellent durability during both OER and HER stability tests at a high current density of 100 mA cm -2 . An electrolyzer, which was assembled with Ni 3 Fe 0.9 Cr 0.1 /CACC electrodes as both the anode and cathode, operates with a low cell voltage of 1.59 V at 10 mA cm -2 . It has been found that the impressive OER activity of Ni 3 Fe 0.9 Cr 0.1 nanoparticles (NPs) can be ascribed to the stimulative formation of the OER-active Ni 3+ /Fe 3+ species by the substituted Cr, while the enhanced HER activity is caused by the Cr substitution, which decreases the water dissociation energy barrier. This work provides an ultrafast and facile strategy to develop electrocatalyst-integrated electrodes with low cost and impressive HER/OER bifunctional performance for overall water splitting.

Organic compounds are promising electrode materials because of their resource sustainability, environmental friendliness, and highly tailorable properties. The porous conjugated polymer shows great potential as an electrode material for its tunable redox nature, conjugated skeleton, and porous structure. Herein, a novel conjugated porous polymer, polydiaminophenylsulfone-triazine, was synthesized by a simple nucleophilic substitution reaction. The conjugated structure and triazine ring can improve the conductivity, charge-transfer efficiency, and physicochemical stability. Also, the porous polymeric framework shows a large specific surface area and high porosity, providing a large contact area with electrolytes and reducing diffusion distance. The polymer demonstrates highly stable cycling performance and good rate capability as an anode for lithium-ion batteries, suggesting a promising strategy to design a competitive electrode material.

Perovskite oxides have attracted much attention for enabling the oxygen-evolution reaction (OER) over the past decades. Nevertheless, their poor conductivity is still a barrier hindering their use. Herein, we report a catalyst prototype of Co-based antiperovskite nitrides CuNCo 3- x V x (0 ≤ x ≤ 1) to be a highly effective OER electrocatalyst. The synthesized CuNCo 3- x V x exhibits greatly enhanced activity and stability toward the OER in alkaline medium. The CuNCo 2.4 V 0.6 shows a mere 235 mV of overpotential to reach 10 mA cm -2 , which is comparable to that of Ir/C (232 mV). More importantly, the CuNCo 2.4 V 0.6 is more durable than the conventional Ir/C catalyst. The CuNCo 2.4 V 0.6 catalyst enabled a Zn-air battery to exhibit a cycle life of 143 h with a much higher cell efficiency. The V-substituted CuNCo 2.4 V 0.6 provides a higher content of the desirable Co 3+ species in the post-OER catalyst, which ensures a high activity over a long-term operation. With these enhanced effects enabled by the compositional flexibility of CuNCo 3- x V x antiperovskite nitride, a feasible strategy for optimizing an electrocatalyst with tunable properties is provided.