Electron/ion-conductive flexible copolymer PEDOT-PDMS (poly(3,4-ethylenedioxythiophene)-poly(dimethylsiloxane)) was successfully developed, which not only effectively optimizes high-voltage NaLiFePO₄F cathode through dripping on electrode surface but also improves high-capacity Si anode through in-situ polymerization on the surface of Si particles. Theoretical calculation and experiments indicate that π-π conjugated structure in PEDOT-PDMS molecular chains easily interacts with PF₆^– anions, providing electron transfer pathways and preventing HF production. Moreover, Li ions transfer through Si-O in the amorphous phase of the copolymer, and its Young’s modulus at rupture is 1.17±0.10 MPa. The in-situ TEM results directly confirm that the polymer layer provides conducting pathways and buffers the stress induced by lithiation. With the NaLiFePO₄F coated cathode, the cells show good cycle stability (~100% of capacity retention after 500 cycles) and high chemical diffusion coefficient of lithium-ions (1.89×10^–9 cm²·s^–1 and 1.20×10^–9 cm²·s^–1). In the case of coated Si anode, a capacity of 1512 mAh·g^–1 is retained after 1000 cycles at 0.5 C with a capacity retention of 69.8% in terms of the highest specific capacity around the 160^th cycle. This work opens a new avenue for the simultaneous optimization of cathode and anode with a functional polymer.

Zinc-ion hybrid supercapacitors (ZHSCs) have been widely considered as promising candidates for flexible electrochemical energy storage devices. The key challenge is to develop hydrogel electrolytes with high hydrophilicity, anti-freezing, bending resistance, and stable interface with electrodes. This study reported a hydrogel electrolyte system that can meet the above functions, in which the zincophilic and negatively charged SO₃⁻, migratable Na⁺, abundant hydrophilic functional groups, gum xanthan, and porous architecture could effectively promote the electrochemical performance of ZHSCs. ZHSCs with such hydrogel electrolytes not only exhibited good low-temperature performance but also showed excellent bending resistance ability. A high specific capacitance could be kept after a long air-working lifespan over 10,000 cycles under a wide operation voltage of 1.85 V at −10 ℃. Furthermore, flexible ZHSCs could maintain the capacitance retention of 93.18% even after continuous 500 bends at an angle of 180°. The designed hydrogel electrolytes could be also used for other electrochemical energy storage devices with anti-freezing and bending resistance by changing electrolyte salt.

Since lithium sulfur (Li-S) energy storage devices are anticipated to power portable gadgets and electric vehicles owing to their high energy density (2600 Wh·kg^–1); nevertheless, their usefulness is constrained by sluggish sulfur reaction kinetics and soluble lithium polysulfide (LPS) shuttling effects. High electrically conductive bifunctional electrocatalysts are urgently needed for Li-S batteries, and high-entropy oxide (HEO) is one of the most promising electrocatalysts. In this work, we synthesize titanium-containing high entropy oxide (Ti-HEO) (TiFeNiCoMg)O with enhanced electrical conductivity through calcining metal-organic frameworks (MOF) templates at modest temperatures. The resulting single-phase Ti-HEO with high conductivity could facilitate chemical immobilization and rapid bidirectional conversion of LPS. As a result, the Ti-HEO/S/KB cathode (with 70 wt.% of sulfur) achieves an initial discharge capacity as high as ~1375 mAh·g^–1 at 0.1 C, and a low-capacity fade rate of 0.056% per cycle over 1000 cycles at 0.5 C. With increased sulfur loading (~5.0 mg·cm^–2), the typical Li-S cell delivered a high initial discharge capacity of ~607 mAh·g^–1 at 0.2 C and showcased good cycling stability. This work provides better insight into the synthesis of catalytic Ti-containing HEOs with enhanced electrical conductivity, which are effective in simultaneously enhancing the LPS-conversion kinetics and reducing the LPS shuttling effect.

Although VB-Group transition metal disulfides (TMDs) VS₂ nanomaterials with specific electronic properties and multiphase microstructures have shown fascinating potential in the field of electromagnetic wave (EMW) absorption, the efficient utilization of VS₂ is limited by the technical bottleneck of its narrow effective absorption bandwidth (EAB) which is attributed to environmental instability and a deficient electromagnetic (EM) loss mechanism. In order to fully exploit the maximal utilization values of VS₂ nanomaterials for EMW absorption through mitigating the chemical instability and optimizing the EM parameters, biomass-based glucose derived carbon (GDC) like sugar-coating has been decorated on the surface of stacked VS₂ nanosheets via a facile hydrothermal method, followed by high-temperature carbonization. As a result, the modulation of doping amount of glucose injection solution (Glucose) could effectively manipulate the encapsulation degree of GDC coating on VS₂ nanosheets, further implementing the EM response mechanisms of the VS₂/GDC hybrids (coupling effect of conductive loss, interfacial polarization, relaxation, dipole polarization, defect engineering and multiple reflections and absorptions) through regulating the conductivity and constructing multi-interface heterostructures, as reflected by the enhanced EMW absorption performance to a great extent. The minimum reflection loss (R_min) of VS₂/GDC hybrids could reach −52.8 dB with a thickness of 2.7 mm at 12.2 GHz. Surprisingly, compared with pristine VS₂, the EAB of the VS₂/GDC hybrids increased from 2.0 to 5.7 GHz, while their environmental stability was effectively enhanced by virtue of GDC doping. Obviously, this work provides a promising candidate to realize frequency band tunability of EMW absorbers with exceptional performance and environmental stability.