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Polymer coatings are emerged as promising candidates for zinc anode artificial solid electrolyte interphase (ASEI) owing to their barrier effect and zincophilicity. However, the poor ionic conductivity of conventional polymer coatings limits their application. Herein, inspired by epidermis function, a porous poly(methylmethacrylate) (PMMA) coating is fabricated to stabilize Zn anode via a novel phase inversion method. The modified Zn anode delivers a remarkable lifespan of over 4000 h at 1 mA cm−2, 1 mAh cm−2, and 120 h at 20 mA cm−2, 20 mAh cm−2 in symmetrical cells. Moreover, porous PMMA‐Zn||NVO full cell also exhibits an excellent cycling stability over 500 cycles at 1 A g−1 as well as an ultralong lifespan exceeding 5000 cycles at 5 A g−1. The excellent cycling stability and rate performance are mainly attributed to the avoided side reactions by the coating protection, as well as the enhanced diffusion and reaction kinetics derived from the good zincophilicity and porous structure of porous PMMA. The facile and universal method for fabricating porous polymer ASEI provides a new insight for the application of conventional polymer materials in Zn anode protection. [ABSTRACT FROM AUTHOR]

Development of low‐cost and high‐efficiency electrocatalysts for overall water splitting is of great significance in the sustainable hydrogen economy. Herein, Fe1.2(CoNi)1.8Sex medium‐entropy metal selenides (MESes) nanoparticles are prepared via the selenylation of metal‐organic frameworks (MOFs) precursors. The optimal Fe1.2(CoNi)1.8Se6 MESe exhibits an outstanding electrocatalytic performance in alkaline media, offering low overpotentials of 66 and 216 mV at 10 mA cm−2 for the hydrogen evolution reaction and oxygen evolution reaction, respectively. A full electrolysis apparatus with Fe1.2(CoNi)1.8Se6 MESe as both cathode and anode displays an excellent performance, achieving 10 mA cm−2 at a potential of 1.55 V. Furthermore, density functional theory calculations demonstrate that the formation of MESe enhances the surface charge density and brings the d‐band center closer to Fermi level, as compared with that of the MOF precursor. Overall, the proposed strategy of medium‐entropy materials presents a low‐cost approach to fabricate energy storage and conversion devices. [ABSTRACT FROM AUTHOR]

Lithium–sulfur (Li–S) batteries are promising alternatives of conventional Li‐ion batteries attributed to their remarkable energy densities and high sustainability. However, the practical applications of Li–S batteries are hindered by the shuttling effect of lithium polysulfides (LiPSs) on cathode and the Li dendrite formation on anode, which together leads to inferior rate capability and cycling stability. Here, an advanced N‐doped carbon microreactors embedded with abundant Co3O4/ZnO heterojunctions (CZO/HNC) are designed as dual‐functional hosts for synergistic optimization of both S cathode and Li metal anode. Electrochemical characterization and theoretical calculations confirm that CZO/HNC exhibits an optimized band structure that effectively facilitates ion diffusion and promotes bidirectional LiPSs conversion. In addition, the lithiophilic nitrogen dopants and Co3O4/ZnO sites together regulate dendrite‐free Li deposition. The S@CZO/HNC cathode exhibits excellent cycling stability at 2 C with only 0.039% capacity fading per cycle over 1400 cycles, and the symmetrical Li@CZO/HNC cell enables stable Li plating/striping behavior for 400 h. Remarkably, Li‐S full cell using CZO/HNC as both cathode and anode hosts shows an impressive cycle life of over 1000 cycles. This work provides an exemplification of designing high‐performance heterojunctions for simultaneous protection of two electrodes, and will inspire the applications of practical Li–S batteries. [ABSTRACT FROM AUTHOR]

Accelerating sulfur redox reactions and suppressing the shuttle effect of lithium polysulfide (LiPSs) are crucial for high-performance lithium–sulfur (Li–S) batteries. Herein, we develop a highly efficient bidirectional electrocatalyst (Ti3C2/(NiCo)0.85Se) consisting of 2D Ti3C2 nanosheets loaded with well-dispersed (NiCo)0.85Se nanoparticles. Based on electrochemical analysis and theoretical calculations, the Ti3C2/(NiCo)0.85Se heterostructure is demonstrated to provide abundant active sites for steady bidirectional electrocatalysis and abundant lithiophilic–sulfiphilic anchoring points for the immobilization of LiPSs. Ti3C2 promotes the reduction process of LiPSs to Li2S, and (NiCo)0.85Se enhances the decomposition of Li2S. Moreover, the (NiCo)0.85Se nanoparticles prevent the Ti3C2 nanosheets from aggregating, ensuring a hierarchical porous framework endowed with good structural robustness and fast electron/ion transportation. Li–S batteries with Ti3C2/(NiCo)0.85Se modified separators exhibit an ultralong cycling lifespan with a capacity decay rate of only 0.03% per cycle over 2000 cycles at 1C and improved rate capability. When equipped with a high sulfur loading of 6.4 mg cm−2 and a low electrolyte/sulfur ratio of 8 μL mg−1, the cell maintains a distinguished area capacity of 9.7 mA h cm−2. This work provides a general strategy for the design of bidirectional electrocatalysts for high-performance Li–S batteries with especially remarkable cycling stability. [ABSTRACT FROM AUTHOR]

The development of bifunctional electrocatalysts with excellent performance in both the hydrogen evolution reaction (HER) and sulfide oxidation reaction (SOR) remains a formidable challenge. Herein, we experimentally synthesize a NiO/RuO 2 p-n heterojunction nanofoam that exhibits highly desirable electrocatalytic properties for both the HER and the SOR. We further design an electrolytic cell by pairing alkaline HER with SOR utilizing the NiO/RuO 2 heterojunction nanofoam as both the anode and the cathode, which demands a low applied voltage of 0.846 V to achieve a current density of 10 mA cm -2 . Density functional theory calculations confirm that the formation of the NiO/RuO 2 p-n heterojunction nanofoam effectively regulates the electronic structure, thereby boosting the electrocatalytic performances for both HER and SOR. This work not only provides a novel strategy to prepare an efficient and stable nanofoam electrocatalyst for hydrogen production but also highlights the potential application of oxide heterojunction electrocatalysts in treating sulfur-containing waste liquid.

Driven by the strong adsorptive and catalytic ability of metal sulfides for soluble polysulfides, it is considered as a potential mediator to resolve the problems of shuttle effect and slow reaction kinetics of polysulfides in lithium-sulfur (Li-S) batteries. However, their further development is limited by poor electrical conductivity and bad long-term durability. Herein, one type of new catalyst composed of SnS/SnS 2 heterostructures on hierarchical porous carbon (denoted as SnS/SnS 2 -HPC) by a simple hydrothermal method is reported and used as an interlayer coating on the conventional separator for blocking polysulfides. The SnS/SnS 2 -HPC integrates the advantages of a porous conductive network for promoting the transport of electrons and an enhanced electrocatalyst for accelerating polysulfides conversion. As a result, such a cell coupled with a SnS/SnS 2 -HPC interlayer exhibits a long-term lifespan of 1200 cycles. This work provides a new cell configuration by using heterostructures with a built-in electric field formed from a p-n heterojunction to improve the performance of Li-S batteries.