A wet-processed, binder-free sulfur cathode integrated with a dual-functional separator for flexible Li-S batteries

Conductive Polymer-Based Interlayers in Restraining the Polysulfide Shuttle of Lithium-Sulfur Batteries

Lithium-sulfur batteries (LSBs) are considered a promising candidate for next-generation energy storage devices due to the advantages of high theoretical specific capacity, abundant resources and being environmentally friendly. However, the severe shuttle effect of polysulfides causes the low utilization of active substances and rapid capacity fading, thus seriously limiting their practical application. The introduction of conductive polymer-based interlayers between cathodes and separators is considered to be an effective method to solve this problem because they can largely confine, anchor and convert the soluble polysulfides. In this review, the recent progress of conductive polymer-based interlayers used in LSBs is summarized, including free-standing conductive polymer-based interlayers, conductive polymer-based interlayer modified separators and conductive polymer-based interlayer modified sulfur electrodes. Furthermore, some suggestions on rational design and preparation of conductive polymer-based interlayers are put forward to highlight the future development of LSBs.

Recent Advances of Freestanding Cathodes for Li-S Batteries

Lithium-sulfur batteries (LSBs) with high energy density and low cost have been recognized as one of the most promising next-generation energy storage systems. Although it has taken decades of development, the practical application of LSBs has been hindered by several inherent obstacles, particularly the severe shuttle effect and sluggish reaction kinetics in the sulfur cathode. Various strategies have been proposed to address these problems via rational design of electrode materials and configurations. Freestanding sulfur cathode could be a promising strategy to improve the sulfur mass loading at the cathode level and energy density of LSBs. This minireview will briefly summary the recent advances in freestanding cathodes for LSBs. The advantages and disadvantages of various freestanding cathodes are discussed and the prospects for the development of flexible cathodes are envisioned.

Tunable Synthesis of Hierarchical Yolk/Double-Shelled SiOx @TiO2 @C Nanospheres for High-Performance Lithium-Ion Batteries

This work reports the preparation of unique hierarchical yolk/double-shelled SiO_x @TiO₂ @C nanospheres with different voids by a facile sol-gel method combined with carbon coating. In the preparation process, SiO_x nanosphere is used as a hard template. Etch time of SiO_x yolk affects the morphology and electrochemical performance of SiO_x @TiO₂ @C. With the increase in etch time, the yolk/double-shelled SiO_x @TiO₂ @C with 15 and 30 nm voids and the TiO₂ @C hollow nanospheres are obtained. The yolk/double-shelled SiO_x @TiO₂ @C nanospheres exhibit remarkable lithium-ion battery performance as anodes, including high lithium storage capacity, outstanding rate capability, good reversibility, and stable long-term cycle life. The unique structure can accommodate the large volume change of the SiO_x yolk, provide a unique buffering space for the discharge/charge processes, improve the structural stability of the electrode material during repeated Li⁺ intercalation/deintercalation processes, and enhance the cycling stability. The SiO_x @TiO₂ @C with 30 nm void space exhibits a high discharge specific capacity of ≈1195.4 mA h g^-1 at the current density of 0.1 A g^-1 after 300 cycles and ≈701.1 mA h g^-1 at 1 A g^-1 for over 800 cycles. These results suggest that the proposed particle architecture is promising and may have potential applications in improving various high performance anode materials.

Vapor phase polymerized conducting polymer/MXene textiles for wearable electronics

Multifunctional electronic textiles hold great potential applications in the wearable electronics field. However, it remains challenging to seamlessly integrate the multiple functions on the textile substrates without sacrificing their intrinsic properties. Herein, we report a novel and facile vapor phase polymerization (VPP) and spray-coating strategy towards the construction of a laminated film containing a PEDOT film and Ti3C2Tx MXene sheets on the fiber surface. The fabricated PEDOT/MXene decorated cotton fabrics are integrated with excellent electrochemical performance, joule heating performance, good electromagnetic interference (EMI) shielding, and strain sensing performance. The resultant multifunctional textiles have a low sheet resistance of 3.6 Ω sq-1, and the assembled all-solid-state fabric supercapacitors exhibit an ultrahigh specific capacitance of 1000.2 mF cm-2, which exceeds the state-of-the-art MXene-based fabric supercapacitors. In addition, the PEDOT/MXene modified fabrics exhibit an exceptional joule heating performance of 193.1 °C at the applied voltage of 12 V, high EMI shielding effectiveness of 36.62 dB, and high sensitivity as strain sensors for human motion detection. This work provides a novel strategy for the structure design of multifunctional textiles and will lay the foundation for the development of multifunctional wearable electronics.