Search

• Engineering crystal growth and surface modification regulate the electron/ion transport behavior in anatase TiO 2. • Pseudocapacitive behavior are essential for fast charging with p-TiO 2 @NC anode. • Three-in-one strategy on TiO 2 surfaces enables robust interface chemistry. • Revealing sodium battery gas generation for safer practical applications. Sodium-ion batteries are a potential candidate for next-generation energy storage devices. Unfortunately, developing an anode with improved long-term cycling stability and high-rate performance remains a substantial problem. In this work, we develop that the Na+ intercalation pseudocapacitance in faceted titanium dioxide endows extreme fast charging and long cycle life in a sodium-ion battery. Theoretical calculations and comprehensive characterization exhibit that high ionic conductivity, stable solid electrolyte interphase (SEI), and pseudocapacitive behavior are essential for fast charging. This well-designed electrode demonstrates a significantly high reversible capacity of about 135 mAh g−1 at 90 C (∼30 A g−1) for 10,000 cycles with an 87.8% retension. Coupled with a vanadium phosphate sodium Na 3 V 2 (PO 4) 3 cathode, and this full cell displays a specific capacity of 310 mAh g−1 at 0.2 A g−1 for 100 cycles. This study unveils the key mechanisms for fast-charging sodium storage, and can also facilitate the improvement of other titanium-based anodes secondary batteries. [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]