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• NiCo 2 O 4 nanoparticles with different morphologies were prepared via template method and self-assembly method. • The NiCo 2 O 4 nanoparticles were in-situ decorated onto porous carbon (PC) and used as host of sulfur cathode for lithium sulfur battery. • The synergistic effect of physical binding of PC and adsorption catalysis of NiCo 2 O 4 nanoparticles could effectively improve the performance of lithium sulfur battery. Lithium-sulfur battery (LSB) is one of the most appealing candidates for advanced next-generation electrochemical energy storage systems based on the merits of extraordinary theoretical specific energy density, abundant resources and environmental friendliness of sulfur. However, the "shuttle effect" of lithium polysulfides (LiPSs) and low utilization of sulfur cathode severely plague the large-scale commercialization of the LSBs. In this work, a novel host material for sulfur cathode, namely porous carbon (PC) decorated with NiCo 2 O 4 nanoparticles (NiCo 2 O 4 /PC), was designed and prepared. Among all tested NiCo 2 O 4 nanoparticles with different morphologies, the NiCo 2 O 4 nanoparticles with honeycomb pore shape (C-NiCo 2 O 4) showed excellent performance as sulfur cathode host. Benefiting from the synergistic advantages between PC and C-NiCo 2 O 4 nanoparticles, the C-NiCo 2 O 4 /PC host materials showed strong adsorption for LiPSs, promising the alleviation of shuttle effect and promoting the catalytic conversion process of LiPSs. As a result, the LSBs with S@C-NiCo 2 O 4 /PC cathode delivered a high specific capacity of 1065.2 mAh g−1 at 0.1C, a stable cycling over 500 cycles with low fading rate of 0.053% per cycle at 0.5C and an enhanced rate capability compared with those of S@C-NiCo 2 O 4 and S@PC cathodes. This work demonstrated the synergistic effect of physical shackle from PC and adsorption-catalysis from NiCo 2 O 4 nanoparticles, which might provide new insights into the optimization of carbonaceous architecture for rationally regulating the polysulfide redox reactions. [ABSTRACT FROM AUTHOR]

Lithiophilic COF@PP separator (TpPa-SO 3 H@PP) was prepared through the strategy combining with in-situ interfacial polymerization reducing the interfacial resistance and lithiophilic groups engineering which can suppress the shuttle effect and facilitate Li+ migration, and it exhibits superior performances. [Display omitted] • In situ interfacial synthesis promotes on preparing COF or POP modified PP separator. • Lithiophilic groups prominently facilitate Li+ transport and suppress shuttle effect. • Batteries with modified separators exhibit superior electrochemical performances. Lithium–sulfur batteries have been considered one of the most promising energy storage devices because of their high energy density (2600 W·h·kg−1), low cost, and the environmental friendliness of sulfur. However, the shuttle effect caused by the soluble polysulfide produced by the sulfur cathode in the redox process seriously affects the commercialization of the battery. To solve such problems, we designed and synthesized a lightweight covalent organic framework (COF)–based TpPa–SO 3 H@PP separator through in situ interfacial polymerization. Benefiting from the lithiophilic –SO 3 H groups, which are arranged in the nanochannels of the TpPa–SO 3 H COF, the TpPa–SO 3 H@PP separator not only suppresses the shuttle of polysulfide but also facilitates Li+ migration. Moreover, the good wettability of the electrolyte to the TpPa–SO 3 H@PP separator resulted in a lower interfacial resistance and higher ionic conductivity, ensuring a higher energy density. Based on the above advantages, cells with the TpPa–SO 3 H@PP separator showed an initial specific capacity of 863.97 mAh g−1 at 1C, and a capacity of 645.62 mAh g−1 after 500 cycles, and the average capacity decay rate of each cycle was only 0.05%, indicating superior cycling performance. Significantly, we extended the in situ interfacial polymerization to the preparation of a lithiophilic amorphous porous organic polymer (POP)–based TpPa–COOH@PP separator, which also has good performance, demonstrating the universality and effectiveness of in situ interfacial polymerization. This work opens a new route to prepare lithiophilic COF@PP and POP@PP separators with a lower shuttle effect and higher ion transport via in situ interfacial polymerization for high–performance Li–S batteries. [ABSTRACT FROM AUTHOR]