Flexible Carbon Dots-Intercalated MXene Film Electrode with Outstanding Volumetric Performance for Supercapacitors

2D MXenes have emerged as promising supercapacitor electrode materials due to their metallic conductivity, pseudo-capacitive mechanism, and high density. However, layer-restacking is a bottleneck that restrains their ionic kinetics and active site exposure. Herein, a carbon dots-intercalated strategy is proposed to fabricate flexible MXene film electrodes with both large ion-accessible active surfaces and high density through gelation of calcium alginate (CA) within the MXene nanosheets followed by carbonization. The formation of CA hydrogel within the MXene nanosheets accompanied by evaporative drying endow the MXene/CA film with high density. In the carbonization process, the CA-derived carbon dots can intercalate into the MXene nanosheets, increasing the interlayer spacing and promoting the electrolytic diffusion inside the MXene film. Consequently, the carbon dots-intercalated MXene films exhibit high volumetric capacitance (1244.6 F cm⁻³ at 1 A g⁻¹), superior rate capability (662.5 F cm⁻³ at 1000 A g⁻¹), and excellent cycling stability (93.5% capacitance retention after 30 000 cycles) in 3 m H₂SO₄. Additionally, an all-solid-state symmetric supercapacitor based on the carbon dots-intercalated MXene film achieves a high volumetric energy density of 27.2 Wh L⁻¹. This study provides a simple yet efficient strategy to construct high-volumetric performance MXene film electrodes for advanced supercapacitors.     

Industry-Scale and Environmentally Stable Ti3C2Tx MXene Based Film for Flexible Energy Storage Devices

MXenes, 2D transition metal carbides, and nitrides have attracted tremendous interest because of their metallic conductivity, solution processability, and excellent merits in energy storage and other applications. However, the pristine MXene films often suffer from poor ambient stability and mechanical properties that stem from their polar terminal groups and weak interlayer interactions. Here, a heteroatom doping strategy is developed to tailor the surface functionalities of MXene, followed by the addition of large-sized reduced graphene oxide (rGO) as conductive additives to achieve a scalable production of S, N-MXene/rGO (SNMG-40) hybrid film with high mechanical strength ( ≈ 45 MPa) and energy storage properties (698.5 F cm⁻³). Notably, the SNMG-40 film also demonstrates long-term cycling stability ( ≈ 98% capacitance retention after 30 000 cycles), which can be maintained under ambient condition or immersed in H₂SO₄ electrolyte for more than 100 days. The asymmetric supercapacitor (aMGSC) based on SNMG-40 film shows an ultrahigh energy density of 22.3 Wh kg⁻¹, which is much higher than those previously reported MXene-based materials. Moreover, the aMGSC also provides excellent mechanical durability under different deformation conditions. Thus, this strategy makes MXene materials more competitive for real-world applications such as flexible electronics and electromagnetic interference shielding.     

Controllable Patterning of Porous MXene (Ti3C2) by Metal-Assisted Electro-Gelation Method

Since discovered in 2011, transition metal carbides or nitrides (MXenes) have attracted enormous attention due to their unique properties. Morphology regulation strategies assembling 2D MXene sheets into 3D architecture have endowed the as-formed porous MXene with a better performance in various fields. However, the direct patterning strategy for the porous MXene into integration with multifunctional and multichannel electronic devices still needs to be investigated. The metal-assisted electro-gelation method the authors propose can directly generate porous-structured MXene hydrogel with a tunable feature. By electrolyzing the sacrificial metal, the released metal cations initiate the electro-gelation process during which electrostatic interactions occur between cations and the MXene sheets. A high spatial resolution down to micro-meter level is achieved utilizing the method, enabling high-performance hydrogels with more complex architectures. Electronics prepared through this metal-assisted electro-gelation process have shown promising applications of the porous MXene in energy and biochemical sensing fields. Energy storage devices with a capacitance at 33.3 mF cm⁻² and biochemical sensors show prominent current responses towards metabolites (sensitivity of H₂O₂: 165.6  µ A mm ⁻¹ cm⁻²; sensitivity of DA: 212 nA  µ m ⁻¹ cm⁻²), suggesting that the metal-assisted electro-gelation method will become a prospective technique for advanced fabrication of MXene-based devices.     

Engineering 3D Ion Transport Channels for Flexible MXene Films with Superior Capacitive Performance

2D MXene materials are of considerable interest for future energy storage. A MXene film could be used as an effective flexible supercapacitor electrode due to its flexibility and, more importantly, its high specific capacitance. However, although it has excellent electronic conductivity, sluggish ionic kinetics within the MXene film becomes a fundamental limitation to the electrochemical performance. To compensate for the relative deficiency, MXene films are frequently reduced to several micrometer dimensions with low mass loading (<1 mg cm^?2), to the point of detriment of areal performance and commercial value. Herein, for the first time, the design of a 3D porous MXene/bacterial cellulose (BC) self‐supporting film is reported for ultrahigh capacitance performance (416 F g^?1, 2084 mF cm^?2) with outstanding mechanical properties and high flexibility, even when the MXene loading reaches 5 mg cm^?2. The highly interconnected MXene/BC network enables both excellent electron and ion transport channel. Additionally, a maximum energy density of 252 µWh cm^?2 is achieved in an asymmetric supercapacitor, higher than that of all ever‐reported MXene‐based supercapacitors. This work exploits a simple route for assembling 2D MXene materials into 3D porous films as state‐of‐the‐art electrodes for high performance energy storage devices.     

Metal Single-Site Molecular Complex–MXene Heteroelectrocatalysts Interspersed Graphene Nanonetwork for Efficient Dual-Task of Water Splitting and Metal–Air Batteries

Development of multifunctional electrocatalysts with high efficiency and stability is of great interest in recent energy conversion technologies. Herein, a novel heteroelectrocatalyst of molecular iron complex (Fe_MC)-carbide MXene (Mo₂TiC₂T_x) uniformly embedded in a 3D graphene-based hierarchical network (GrH) is rationally designed. The coexistence of Fe_MC and MXene with their unique interactions triggers optimum electronic properties, rich multiple active sites, and favorite free adsorption energy for excellent trifunctional catalytic activities. Meanwhile, the highly porous GrH effectively promotes a multichannel architecture for charge transfer and gas/ion diffusion to improve stability. Therefore, the Fe_MC–MXene/GrH results in superb performances towards oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER) in alkaline medium. The practical tests indicate that Zn/Al–air batteries derived from Fe_MC–MXene/GrH cathodic electrodes produce high power densities of 165.6 and 172.7 mW cm⁻², respectively. Impressively, the liquid-state Zn–air battery delivers excellent cycling stability of over 1100 h. In addition, the alkaline water electrolyzer induces a low cell voltage of 1.55 V at 10 mA cm⁻² and 1.86 V at 0.4 A cm⁻² in 30 wt.% KOH at 80 °C, surpassing recent reports. The achievements suggest an exciting multifunctional electrocatalyst for electrochemical energy applications.     

Triple Interface Optimization of Ru-based Electrocatalyst with Enhanced Activity and Stability for Hydrogen Evolution Reaction

A challenging task is to promote Ru atom economy and simultaneously alleviate Ru dissolution during the hydrogen evolution reaction (HER) process. Herein, Ru nanograins (≈1.7 nm in size) uniformly grown on 1T-MoS₂ lace-decorated Ti₃C₂T_x MXene sheets (Ru@1T-MoS₂-MXene) are successfully synthesized with three types of interfaces (Ru/MoS₂, Ru/MXene, and MoS₂/MXene). It gives high mass activity of 0.79 mA µg_Ru⁻¹ at an overpotential of 100 mV, which is ≈36 times that of Ru NPs. It also has a much smaller Ru dissolution rate (9 ng h⁻¹), accounting for 22% of the rate for Ru NPs. Electrochemical tests, scanning electrochemical microscopy measurements combined with DFT calculations disclose the role of triple interface optimization in improved activity and stability. First, 2D MoS₂ and MXene can well disperse and stabilize Ru grains, giving larger electrochemical active area. Then, Ru/MoS₂ interfaces weakening H^* adsorption energy and Ru/MXene interfaces enhancing electrical conductivity, can efficiently improve the activity. Next, MoS₂/MXene interfaces can protect MXene sheet edges from oxidation and keep 1T-MoS₂ phase stability during the long-term catalytic process. Meanwhile, Ru@1T-MoS₂-MXene also displays superior activity and stability in neutral and alkaline media. This work provides a multiple-interface optimization route to develop high-efficiency and durable pH-universal Ru-based HER electrocatalysts.     

Nature-Inspired Interconnected Macro/Meso/Micro-Porous MXene Electrode

The geometric multiplication development of MXene has promoted it to become a star material in numerous applications including, but not limited to, energy storage. It is found that pore structure modulation engineering can improve the inherent properties of MXene, in turn significantly enhancing its electrochemical performance. However, most of the current works have focused on exploring the structure-effective relationships of the single-scale pore structure regulation of MXene. Inspired by Murray's law from nature where a highly graded structure of the organisms is discovered and used to achieve effective diffusion and maximize mass transfer, a hierarchically interconnected porous MXene electrode across micro-meso-macroporous is constructed. This MXene-based electrode provides large amounts of active sites while greatly shortening the ion diffusion channel. Finally, the zinc ion microcapacitor based on this MXene electrode exhibits an ultrahigh area-specific capacitance up to 410 mF cm⁻² and an energy density up to 103 µWh cm⁻² at a power density of 2100 µW cm⁻². The areal energy density outperforms the currently reported zinc ion microcapacitors. This study supports an effective strategy for electrode materials (including but not limited to MXene) to achieve ultra-short ion diffusion channels and maximum transport efficiency for next-generation high-performance energy storage.     

An Ultrafast,High-Loading,and Durable Poly(p-aminoazobenzene)/Reduced Graphene Oxide Composite Electrode for Supercapacitors

Although challenging, the fabricated supercapacitor electrodes with excellent rate capability, long cycling stability, and high mass-loading are crucial for practical applications. Herein, a novel 3D porous poly(p-aminoazobenzene)/reduced graphene oxide hydrogel is designed and prepared as an ultrafast, high-loading, and durable pseudocapacitive electrode through a facile two-step self-assembly approach. Owing to abundant stable redox-active sites, fast electrolyte diffusion, and efficient charge conduction, the PRH electrode (5 mg cm⁻²) shows a high specific capacitance (701 F g⁻¹ at 2 A g⁻¹) and ultrafast rate (97% capacitance retention at 100 A g⁻¹). Furthermore, even with a mass-loading of 10 mg cm⁻², the electrode still exhibits comparable high performance and excellent long-term cycling life (only 6.7% capacitance loss after 10 000 cycles). This work demonstrates novel polyaniline analog composites for constructing novel electrodes, promising to open an avenue toward practical applications.     

On the Practical Applicability of Rambutan-like SiOC Anode with Enhanced Reaction Kinetics for Lithium-Ion Storage

Silicon oxycarbide (SiOC) possesses great potential in lithium-ion batteries owing to its tunable chemical component, high reversible capacity, and small volume expansion. However, its commercial application is restricted due to its poor electrical conductivity. Herein, rambutan-like vertical graphene coated hollow porous SiOC (Hp-SiOC@VG) spherical particles with an average diameter of 302 nm are fabricated via a hydrothermal treatment combined CH₄ pyrolysis strategy for the first time. As-prepared Hp-SiOC@VG exhibits a large reversible capacity of 729 mAh g⁻¹ at 0.1 A g⁻¹, remarkable cycling stability of 98% capacity retention rate after 600 cycles at 1.0 A g⁻¹ and high rate capability of 289 mAh g⁻¹ at 5.0 A g⁻¹ owing to the unique structure of the particles and the electrical conductivity of the vertical graphene. Density functional theory calculations reveal that the higher contents of SiO₃C and SiO₂C₂ structural units in the SiOC are beneficial to enhance the Li⁺ storage capacity. Additionally, the full-cell assembled with Hp-SiOC@VG and LiFePO₄ delivers up to 74% capacity retention rate after 100 cycles at 0.2 A g⁻¹. This work reports a new way for the facile preparation of template-free hollow porous materials and expands the application prospects of SiOC-based anode for lithium-ion batteries.     

Grafted MXenes Based Electrolytes for 5V-Class Solid-State Batteries

Polymer blends based solid polymer electrolytes (SPEs), combining the advantages of multiple polymers, are promising for the utilization of 5 V-class cathodes (e.g., LiCoMnO₄ (LCMO)) with enhanced safety. However, severe macro-phase separation with defects and voids in polymer blends restrict the electrochemical stability and ionic migration of SPEs. Herein, inorganic compatibilizer polyacrylonitrile grafted MXene (MXene-g-PAN) is exploited to improve the miscibility of the poly(vinylidene fluoride-co-hexafluoropropylene) (PVHF)/PAN blends and suppress the consolidation of phase particles. The resulting SPE exhibits a high anodic stability with an ionic conductivity of 2.17 × 10⁻⁴ S cm⁻¹, enabling a stable and reversible Li platting/stripping (over 2500 h). The fabricated solid Li‖LCMO cell delivers a 5.1 V discharge voltage with a decent capacity (131 mAh g⁻¹) and cycling performance. Subsequently, the solid all-in-one graphite‖LCMO battery is also constructed to extend the application of MXene based SPEs in flexible batteries. Benefiting from the interface-less design, outstanding mechanical flexibility and stability is achieved in the battery, which can endure various deformations with a low-capacity loss (< ≈10%). This study signifies a significant development on solid flexible lithium ion batteries with enhanced performance, stability, and reliability by investigating the miscibility of polymer blends, benefiting for the design of high-performance SPEs.     

Lamellar MXene Composite Aerogels with Sandwiched Carbon Nanotubes Enable Stable Lithium–Sulfur Batteries with a High Sulfur Loading

Realizing long cycling stability under a high sulfur loading is an essential requirement for the practical use of lithium–sulfur (Li–S) batteries. Here, a lamellar aerogel composed of Ti₃C₂T_x MXene/carbon nanotube (CNT) sandwiches is prepared by unidirectional freeze-drying to boost the cycling stability of high sulfur loading batteries. The produced materials are denoted parallel-aligned MXene/CNT (PA-MXene/CNT) due to the unique parallel-aligned structure. The lamellae of MXene/CNT/MXene sandwich form multiple physical barriers, coupled with chemical trapping and catalytic activity of MXenes, effectively suppressing lithium polysulfide (LiPS) shuttling under high sulfur loading, and more importantly, substantially improving the LiPS confinement ability of 3D hosts free of micro- and mesopores. The assembled Li–S battery delivers a high capacity of 712 mAh g⁻¹ with a sulfur loading of 7 mg cm⁻², and a superior cycling stability with 0.025% capacity decay per cycle over 800 cycles at 0.5 C. Even with sulfur loading of 10 mg cm⁻², a high areal capacity of above 6 mAh cm⁻² is obtained after 300 cycles. This work presents a typical example for the rational design of a high sulfur loading host, which is critical for the practical use of Li–S batteries     

Antifreezing Zwitterionic Hydrogel Electrolyte with High Conductivity of 12.6 mS cm−1 at −40 °C through Hydrated Lithium Ion Hopping Migration

Hydrogel electrolytes have high room-temperature conductivity and can be widely used in energy storage device. However, hydrogels suffer from the inevitable freezing of water at subzero temperatures, resulting in the diminishment of their conductivity and mechanical properties. How to achieve high conductivity without sacrificing hydrogels’ flexibility at subzero temperature is an important challenge. To address this challenge, a new type of zwitterionic polymer hydrogel (polySH) electrolytes is fabricated. The anionic and cationic counterions on the polymer chains facilitate the dissociation of LiCl. The antifreezing electrolyte can be stretched to a strain of 325% and compressed to 75% at −40 °C and possesses an outstanding conductivity of 12.6 mS cm⁻¹ at −40 °C. A direct hopping migration mechanism of hydrated lithium-ion through the channel of zwitterion groups is proposed. The polySH electrolyte-based-supercapacitor (SC) exhibits a high specific capacitance of 178 mF cm⁻² at 60 °C and 134 mF cm⁻² at −30 °C with a retention of 81% and 71% of the initial capacitance after 10 000 cycles, respectively. The overall merits of the electrolyte will open up a new avenue for advanced ionic conductors and energy storage device in practical applications.     

Development of Fluorine-Free Tantalum Carbide MXene Hybrid Structure as a Biocompatible Material for Supercapacitor Electrodes

The application of nontoxic 2D transition-metal carbides (MXenes) has recently gained ground in bioelectronics. In group-4 transition metals, tantalum possesses enhanced biological and physical properties compared to other MXene counterparts. However, the application of tantalum carbide for bioelectrodes has not yet been explored. Here, fluorine-free exfoliation and functionalization of tantalum carbide MAX-phase to synthesize a novel Ta₄C₃T_x MXene-tantalum oxide (TTO) hybrid structure through an innovative, facile, and inexpensive protocol is demonstrated. Additionally, the application of TTO composite as an efficient biocompatible material for supercapacitor electrodes is reported. The TTO electrode displays long-term stability over 10 000 cycles with capacitance retention of over 90% and volumetric capacitance of 447 F cm⁻³ (194 F g⁻¹) at 1 mV s⁻¹. Furthermore, TTO shows excellent biocompatibility with human-induced pluripotent stem cells-derived cardiomyocytes, neural progenitor cells, fibroblasts, and mesenchymal stem cells. More importantly, the electrochemical data show that TTO outperforms most of the previously reported biomaterials-based supercapacitors in terms of gravimetric/volumetric energy and power densities. Therefore, TTO hybrid structure may open a gateway as a bioelectrode material with high energy-storage performance for size-sensitive applications.     

Biomass-Derived Inks with Tailored Pteridine Derivatives for Sustainable Printed Micro-Supercapacitors

Using biological redox compounds holds great potential in designing sustainable energy storage systems, but it is essential for structure optimization of biological redox centers and in-depth studies regarding their underlying energy storage mechanisms. Herein, a molecular simplification strategy is proposed to tailor the redox unit of pteridine derivatives, an essential component of ubiquitous electron transfer proteins in nature. The tailored pteridine derivatives can be combined with biomass holey graphene (BHG) to fabricate an ink with a micrometer-scale resolution for printing flexible electrodes for micro-supercapacitor (MSCs). The reversible tautomerism of pteridine derivatives from alloxazinic to isoalloxazinic structure is first unveiled in supercapacitors. Through molecular tailoring, printed MSC electrodes using pteridine derivatives/BHG ink demonstrate excellent charge storage, outstanding areal capacitance (95.3 mF cm⁻² at 0.1 mA cm⁻²), energy density (16.3 µWh cm⁻²), power density (208 µW cm⁻²), long-term cycling performance (90.5% retention after 10 000 cycles), easy integration, and exceptional flexibility (maintaining capacitance at various bending states). The non-covalent interaction of tailored pteridine molecules with redox centers and biomass porous graphene suggests a mature screen-printing technology for fabricating a sustainable energy storage system with a rational MSC configuration.     

A Conductive 2D Conjugated Tetrathia[8]circulene-Based Nickel Metal–Organic Framework for Energy Storage

Herein, a novel D₄ symmetrical redox-active ligand tetrathia[8]circulene-2,3,5,6,8,9,11,12-octaol (8OH-TTC) is designed and synthesized, which coordinates with Ni²⁺ ions to construct a 2D conductive metal-organic framework (2D c-MOF) named Ni-TTC. Ni-TTC exhibits typical semiconducting properties with electrical conductivity up to ≈1.0 S m⁻¹ at 298 K. Furthermore, magnetism measurements show the paramagnetic property of Ni-TTC with strong antiferromagnetic coupling due to the presence of semiquinone ligand radicals and Ni²⁺ sites. In virtue of its decent electrical conductivity and good redox activity, the gravimetric capacitance of Ni-TTC is up to 249 F g⁻¹ at a discharge rate of 0.2 A g⁻¹, which demonstrates the potential of tetrathia[8]circulene-based redox-active 2D c-MOFs in energy storage applications.     

Optimized Ti?O Subcompounds and Elastic Expanded MXene Interlayers Boost Quick Sodium Storage Performance

To develop quick-charge sodium-ion battery, it is significant to optimize insertion-type anode to afford fast Na⁺ diffusion rate and excellent electron conductivity. First-principles calculations reveal the Ti O subcompound superiority for Na⁺ diffusion following Ti(II) O > Ti(III) O > Ti(IV) O. Hence, in situ growth of amorphous Ti O subcompounds with rich oxygen defects based on Ti₃C₂T_x-MXene is developed. Meanwhile, the composite presents expanded MXene interlayer spacing and much enhanced conductivity. The synergistic effect of enhanced electron/ion conduction gives a high capacity of 107 mAh g⁻¹ at 50 A g⁻¹, which gives 50% and 150% increasements compared with one counterpart without valence adjustment and another one without MXene expansion. It only needs 20 s (at 30 A g⁻¹) to complete the discharge/charge process and obtains a capacity of 144.5 mAh g⁻¹, which also shows a long-term cycling stability at quick-charge mode (121 mAh g⁻¹ after 10000 cycles at 10 A g⁻¹). The enhanced performance comes from fast electron transfer among Ti O subcompounds contributed by rich-defect amorphous TiO_2–x, and a reversible change of elastic MXene with interlayer spacing between 1.4 and 1.9 nm during Na⁺ insertion/extraction process. This study provides a feasible route to boost the kinetics and develop quick-charge sodium-ion battery.     

Layered Double Hydroxide with Interlayer Quantum Dots and Laminate Defects for High-Performance Supercapacitor

Owing to the flexible adjustability of laminates, layered double hydroxides (LDHs) can achieve enhanced conductivity and capacitance. However, the regulation of interlayer activity is a great challenge because of the unconquerable charge repulsion between laminates. Herein, a dual-activity design of LDHs is uniquely realized, including laminate defects and interlayer ZnS quantum dots (QDs). Via pre-embedding Zn2+ and controllable vulcanization, ZnS-QDs interpenetrate between CuCo-LDH layers, exposing abundant active sites and widening the layer spacing. Meanwhile, sulfur replaces part of the oxygen on the laminates to form rich oxygen vacancies (CuCo-LDH-S), which does not damage the layered spatial structure and ensures the fast ions/electron transport. Theoretical calculations indicate that the new active centers exhibit higher charge density as compared to CuCo-LDH. Moreover, the copper foam directly provides copper source to ensure that CuCo-LDH-S/ZnS-QDs present a 3D self-supporting structure with ultrastability. Hence, it delivers an ultrahigh capacitance of 7.82 F cm⁻² at 2 mA cm⁻² and 4.43 F cm⁻² at 20 mA cm⁻². The hybrid supercapacitors display an outstanding energy density of 299 µWh cm⁻² at power density of 1600 µW cm⁻², with outstanding capacitance retention of 102.3% and coulomb efficiency of 96.2% after 10 000 cycles.     

MXene/Fluoropolymer-Derived Laser-Carbonaceous All-Fibrous Nanohybrid Patch for Soft Wearable Bioelectronics

While state-of-the-art skin-adhering fibrous electrodes have distinct benefits in personal wearable bioelectronics, considerable challenges persist in the production of fibrous-based soft conductive biosensing nanomaterials and their integration into efficient multisensing platforms. Here, an electrochemical-electrophysiological multimodal biosensing patch based on MXene/fluoropolymer nanofiber-derived hierarchical porous TiO₂ nanocatalyst interconnected 3D fibrous carbon nanohybrid electrodes is reported. The nanohybrid electrode is produced via a one-step laser carbonaceous thermal oxidation, resulting in excellent elctroconductivity (sheet resistance = 15.6 Ω sq⁻¹), rich active edges for effective electron transmission, and abundant support for enzyme immobilization. The features are attributed to three synergistic effects: i) conductivity of the interior, unoxidized MXene layers, ii) quick heterogeneous electron transmission of the exterior TiO₂ nanoparticles, and iii) the porous disordered carbon's electron “bridge” effects. Based on the foregoing, the nanohybrid modified biosensing patch integrated into textile is demonstrated to be capable of simultaneously and precisely monitoring sweat glucose with pH adjustment (sensitivity of 77.12 µA mm ⁻¹ cm⁻² within physiological concentrations of 0.01–2 × 10⁻³ m ) and electrocardiogram signals (signal-to-noise ratio = 37.63 dB). This novel approach paves the way for controlled investigations of the nanohybrid, for several functionalization and design options, and for the mass manufacturing capabilities required in real-world applications.     

Boosting Potassium Storage Kinetics,Stability, and Volumetric Performance of Honeycomb-Like Porous Red Phosphorus via In Situ Embedding Self-Growing Conductive Nano-Metal Networks

Large volume expansion and sluggish reaction kinetics of low-conductivity red phosphorus (RP) anodes hinder its practical application in potassium-ion batteries (PIBs). Here, a self-limited growth strategy to fabricate Bi (Sb) nanoparticles is demonstrated, as electrochemically active and conductive coating, in situ embedded into honeycomb-like porous red phosphorus (HPRP) to form HPRP@Bi (HPRP@Sb) composites, greatly improving the potassium-storage kinetics, stability and volumetric performance of HPRP. Here, Bi nanoparticles are converted into amorphous Bi during cycling, which are uniformly coated on the porous HPRP skeleton to form 3D conductive Bi networks. Theoretical calculations verify that introducing amorphous Bi significantly decreases K⁺ diffusion barrier in composites, and greatly enhancing their electrical conductivity and interfacial ion transport between HPRP and Bi, thereby accelerating their potassium storage kinetics and stability. Whereas the robust porous structure and inward expansion mechanism of HPRP effectively buffer their volume expansion of RP and Bi. Therefore, HPRP@Bi anode delivers high gravimetric and volumetric capacity (465.6 mAh g⁻¹, 745 mAh cm⁻³) and stable long lifespan with 200 cycles at 0.05 A g⁻¹ in PIBs. This work demonstrates a new approach to promote ion storage kinetics and stability of RP via integrating the synergy of high-conductivity active metal and high-capacity porous RP.     

A Skin-Bioinspired Urchin-Like Microstructure-Contained Photothermal-Therapy Flexible Electronics for Ultrasensitive Human-Interactive Sensing

Wearable electronic sensors have attracted extensive attention in multifunctional electronic skin, personalized health monitoring, intelligent human–machine interaction, and smart medical treatment. However, critical challenge exists in simultaneously achieving excellent sensing performances with high sensitivity, rapid response, low sensing limit, and excellent cycling stability for full-scale human healthcare detection and further timely photothermal therapy. For highly sensitive human skin, the spinosum microstructure in epidermis and dermis takes an important part in sensing signal amplification and transmission. Inspired by the spinosum microstructure of human skin for highly sensitive tactile perception, a skin-inspired flexible electronic sensor is prepared from the face-to-face assembly of an as-prepared polybutylene adipate-polyurethane (PBAPU) elastomer matrix with conducting MXene nanosheets-coated urchin-like microstructure templated from natural chrysanthemum pollen grain microstructures, and an interdigitated electrode-coated PBAPU elastomer substrate. The PBAPU elastomer matrix is newly prepared, exhibiting outstanding tensile strength (18.87 MPa), high stretchability (1190%), and comparable elastic modulus (1.7 MPa) to human skin. The as-assembled flexible electronic sensor exhibits a highly sensitive sensitivity (up to 784.02 kPa⁻¹), low detection limit (0.12 Pa), and reliable cycling stability for intelligent human–machine interfacing. The MXene nanosheets-coated urchin-like microstructure-contained PBAPU possesses efficient photothermal heating performance to achieve on-demand photothermal therapy for rehabilitation training.