High Electrochemical Stability Research Articles

Constructing fast-ion-diffusion cathode-electrolyte-interphase to improve LiNi0.8Co0.1Mn0.1O2 cathode cyclic stability with composite polymer conductors

As one of the mainstream cathode materials used in power battery, it’s necessary for the LiNixCoyMn1-x-yO2 (NCM) to perform fast charge and discharge capabilities. However, the unstable cathode-electrolyte-interphase (CEI) at high charging/discharging rates causes cycling performance to degrade rapidly. Modified polyaniline (PANI) and polyethylene glycol (PEG) are adsorbed on layer-structured Ni-rich cathode, forming cathode-electrolyte-interphase CEI film with high electro-chemical stability and mechanical strength layer by coordinating interaction of hydrogen bonds with transition metals. When the carbon nanotubes (CNTs) or the -SO2F functional group in bis(trifluoromethane)sulfonimide lithium salt (LiTFSI) enters PANI skeleton, the composition, morphology and thickness of CEI film would be influenced by the CNTs or -SO2F groups. The improved interface would enhance the cathode-electrolyte interface stability by providing a steady channel for Li+ transport. Hence, the optimized CEI film effectively inhibit the occurrence of side reactions, and the capacity retention of NCM@PANIPEG/LiTFSI||Li cells has been improved from ∼ 55% to ∼ 77% at 45 °C and 2.7–4.3 V (vs. Li+/Li) in 100 cycles at 1 C. This low cost and straightforward preparation process exhibit great application prospects in future industrial applications.

Theoretical Screening of Highly Efficient Single-Atom Catalysts Based on Covalent Triazine Frameworks for Oxygen Reduction.

Covalent triazine frameworks (CTFs) obtained from the trimerization of aromatic nitriles are expected to be the preferred carrier for single-atom catalysts (SACs). Using density functional theory methods, the oxygen reduction reaction (ORR) performance of a series of 3d, 4d, and 5d transition metals supported on the 6N or 9N pore of the CTF system [M-CTF(6N) or M-CTF(9N)] is explored. At first, 32 kinds of M-CTF(6N) and M-CTF(9N) are screened out with high thermodynamic and electrochemical stability. The binding energy of ORR intermediates and the change of Gibbs free energy in each step of the ORR are calculated. The overpotential of Pd-CTF(6N) is the lowest, which is 0.38 V. Considering that the ORR activity of M-CTFs is mainly limited by the strong binding of *OH, M-CTF(6N) and M-CTF(9N) are further modified by the OH ligand, namely, M-OH-CTF(6N) and M-OH-CTF(9N). After being modified by the OH ligand, due to the weakened binding strength of *OH, all these screened M-CTFs exhibit better ORR activity. Among them, the η values of Cu-OH-CTF(6N), Pd-OH-CTF(6N), Rh-OH-CTF(6N), Ir-OH-CTF(6N), Rh-OH-CTF(9N), and Ir-OH-CTF(9N) are 0.39, 0.38, 0.24, 0.30, 0.31, and 0.33 V, respectively, which possess better ORR activity than the Pt(111) surface (η = 0.45 V). This work highlights the great potential of CTFs as an efficient carrier for SACs.

Role of ferroelectric nanoparticles coated separator in improvement of capacity retention at high current density on sulfur/SWCNT composite cathodes for Li–S batteries

In this manuscript, we are reporting the role of ferroelectric nanoparticles (FNPs) coated separators in capacity retention at high current density (200 mA/g) on S/SWCNT composite cathodes. The ferroelectric nanoparticles of Bi0.925Gd.075Fe0.95Ni0.05O3 (BGFNO) of spontaneous polarization 2.5 µC/cm2 were coated on commercial separators (PP) as well as doped in sulfur/SWCNT composite cathodes. Our results show a discharge capacity retention of 72% by using commercial separator polypropylene (PP); however, a capacity retention improvement of more than 100% was obtained for FNPs coated separator, which has been placed on the anode side as well as on the cathode side. It is observed that the FNPs coated separator due to spontaneous polarization on the anode and cathode side acts as a repulsive charge on the separator surface to retard polysulfide migration via electrostatic repulsion and protects the surface of lithium from dendrite formation due to which it gains high capacity retention as well as stability. The coated separator controls the transport of carrier ions and side reactions; however, the FNPs doped cathode acts as an absorption center for polysulfides to enhance the electrochemical performance of the cells. The significance of this study is to design an efficient methodology, which could protect electrodes from dendrite formation via coated separator and modified cathode with the FNPs via suppressing the polysulfide formation to achieve high capacity retention and electrochemical cycle stability.

Rare-metal-free Zn–air batteries with ultrahigh voltage and high power density achieved by iron azaphthalocyanine unimolecular layer (AZUL) electrocatalysts and acid/alkaline tandem aqueous electrolyte cells

Zn–air batteries have only been used in limited applications, such as hearing aid batteries, due to their low power density and standard voltage of around 1.4 V. Therefore, to use Zn–air batteries as a drive power source in cutting-edge devices such as drones, it is essential to improve the drive voltage and output power density. Here, we propose Zn–air batteries with a high potential (∼2.25 V) and high power density (∼318 mW/cm2) by using the newly designed iron azaphthalocyanine unimolecular layer (AZUL) electrocatalyst and a tandem Zn–air battery cell. The AZUL electrocatalyst in this new type of cell had a high electrochemical stability and high oxygen reduction reaction performance in the ultralow pH region, in which Pt and other metallic and inorganic electrocatalysts cannot be used. Furthermore, the tandem-electrolyte cells had a cell voltage of over 1.0 V at a high discharge current density of 200 mA/cm2, and the output power density was 1139 mWh/g(Zn) at 100 mA/cm2 discharge.

A scalable one-pot strategy for the development of polymer electrolytes adaptable to room-temperature high-voltage lithium batteries

Poly(ethylene oxide) (PEO) polymer electrolytes (PEs) have been commercially applied in LiFePO4||Li solid-state lithium batteries (SSLBs). However, it remains challenging to develop PEO-based PEs applicable to the high-voltage SSLBs with higher energy density, owing to the poor electrochemical stability of PEO. Herein, we report a scalable strategy for fabricating PEO-based PEs with high-voltage compatibility, by exploiting a new mechanism to stabilize the cathode-electrolyte interface in the high-voltage SSLBs. The protocol only involves a one-pot synthesis procedure to covalently crosslink the PEO chains, in the presence of high-content lithium bis(trifluoromethylsulphonyl)imide (LiTFSI) salts and N,N-dimethylformamide (DMF). LiTFSI-DMF supramolecular aggregates are formed and firmly embedded in the polymer network, endowing the PE with high room-temperature ionic conductivity. The dissociated and highly concentrated TFSI− anions can enter the Helmholtz layer close to the high-voltage cathode, leading to the formation of a thin and homogeneous cathode electrolyte interface (CEI), mainly composed of LiF, on the cathode. The CEI with high electrochemical stability can effectively stabilize the cathode-electrolyte interface, enabling long-term stable cycling of the high-voltage LiCoO2||Li and nickel-rich NCM622||Li batteries at room temperature. The simplicity and scalability of the strategy makes the reported PEO-based PE potentially applicable in high-voltage SSLBs in practice.

Screening Topological Quantum Cathode Materials for K-Ion Batteries by Graph Neural Network and First-Principles Calculations

Among the key parts of metal-ion batteries, cathode materials significantly affect the energy density and cycling stability. However, due to the large size of K+, not much progress has been made on cathode materials for K-ion batteries (KIBs). In this study, using the Atomistic Line Graph Neural Network and first-principles calculations, for the first time we screen cathode materials for KIBs from 7385 topological quantum materials with high electronic conductivity and reversible capacity. The experimentally synthesized K2MnS2 is discovered to have a reversible capacity of 203.8 mAh/g, an energy density of 564.5 Wh/kg, a small volume change of 6.4%, and multiple channels for K+ transport with fast dynamics. Furthermore, K2MnS2 shows high electrochemical interface stability with the reported solid electrolytes of K4V2O7, and K3NbP2O9. These findings suggest that topological quantum materials expand the design space of battery cathodes.

Solid composite electrolyte based on oxygen vacancy effect of Lix(CoCrFeMnNi)O4-y high entropy oxides

Solid-state electrolytes are desired for reliable systems in the battery industry. In this study, high entropy oxide (HEO) composites of Lix(CoCrFeMnNi)3-xO4-y were introduced into a polyethylene oxide (PEO)-based solid composite polymer electrolyte (SCE). Li doping of the HEO compound induces more oxygen vacancies than traditional methods, and this facilitates Li ion transport through the three-dimensional (3D) channel of HEO composites and increases ionic conductivity. The ionic conductivity of the HEO/PEO SCE reached 1 × 10−4 S cm−1 (40°C), significantly higher than that of the PEO solid polymer electrolyte (SPE; 2.8 × 10−5 S cm−1). The tensile strength and elongation of the HEO/PEO SCE were greater by 140.1 % and 138 %, respectively than those of the PEO SPE, resulting in more effective suppression of Li dendrite formation. A solid-state LiFePO4/Li coin cell with the HEO/PEO SCE exhibited a maximum discharge capacity of 127 mAh g−1 at 0.1 C and a high rate capability of 97.2 % at room temperature. The HEO/PEO SCE exhibited superior ionic conductivity, structural integrity, and high thermal and electrochemical stability, making it suitable for safe and high-energy storage systems in Li-ion battery development.

Structural and Dynamic Characterization of Li–Ionic Liquid Electrolyte Solutions for Application in Li-Ion Batteries: A Molecular Dynamics Approach

Pyrrolidinium-based (Pyr) ionic liquids (ILs) have been proposed as electrolyte components in lithium-ion batteries (LiBs), mainly due to their higher electrochemical stability and wider electrochemical window. Since they are not naturally electroactive, in order to allow their use in LiBs, it is necessary to mix the ionic liquids with lithium salts (Li). Li–PF6, Li–BF4, and Li–TFSI are among the lithium salts more frequently used in LiBs, and each anion, namely PF6 (hexafluorophosphate), BF4 (tetrafluoroborate), and TFSI (bis(trifluoromethanesulfonyl)azanide), has its own solvation characteristics and interaction profile with the pyrrolidinium ions. The size of Pyr cations, the anion size and symmetry, and cation–anion combinations influence the Li-ion solvation properties. In this work, we used molecular dynamics calculations to achieve a comprehensive view of the role of each cation–anion combination and of different fractions of lithium in the solutions to assess their relative advantage for Li-ion battery applications, by comparing the solvation and structural properties of the systems. This is the most-comprehensive work so far to consider pyrrolidinium-based ILs with different anions and different amounts of Li: from it, we can systematically determine the role of each constituent and its concentration on the structural and dynamic properties of the electrolyte solutions.

Cellulose-Assisted Vertically Heterostructured PEO-Based Solid Electrolytes Mitigating Li-Succinonitrile Corrosion for Lithium Metal Batteries.

In the field of solid-state lithium metal batteries (SSLMBs), constructing vertically heterostructured poly(ethylene oxide) (PEO)-based solid electrolytes is an effective method to realize their tight contact with cathodes and Li anodes at the same time. Succinonitrile (SN) has been widely used in PEO-based solid electrolytes to improve the interface contact with cathodes, enhance the ionic conductivities, and obtain a high electrochemical stability window of PEO, but its application is still hindered by its intrinsic instability to Li anodes, which results in corrosion and side interactions with lithium metal. Herein, the cellulose membrane (CM) is introduced creatively into the vertically heterostructured PEO-based solid electrolytes to match the PEO-SN solid electrolytes at the cathode side. With the advantage of the interaction between -OH groups of CM and -C≡N groups in SN, the movement of free SN molecules from cathodes to Li anodes is limited effectively, resulting in a stable and durable SEI layer. In specific, the Li||LiFePO4 battery with the CM-assisted vertically heterostructured PEO-based solid electrolyte by in situ preparation delivers a discharge capacity of around 130 mAh g-1 after 300 cycles and capacity retention of 95% after 500 cycles at 0.5 C. Our work provides a solution to construct PEO-based solid electrolytes feasible to match cathodes and Li anodes effectively by intimate contact with electrodes.

Adaptive Ion-Gel: Stimuli-Responsive, and Self-Healing Ion Gels.

Ion gels are an emerging class of polymer gels in which a three-dimensional polymer network swells with an ionic liquid. Ion gels have drawn considerable attention in various fields such as energy and biotechnology owing to their excellent properties including nonvolatility, nonflammability, high ionic conductivity, and high thermal and electrochemical stability. Since the first report on ion gels (published ∼30 years ago), diverse functional ion gels exhibiting impressive physicochemical properties have been reported. In this review, recent developments in functional ion gels that can modulate their physical properties in response to environmental conditions are outlined. Stimuli-responsive ion gels that can adaptively undergo phase transitions in response to thermal and light stimuli are initially discussed, followed by an evaluation of diverse self-healing ion gels that can spontaneously mend mechanical damage through judiciously designed ion-gel networks.

All‐Polymer Fiber Organic Electrochemical Transistor for Chronic Chemical Detection in the Brain

AbstractContinuous and precise monitoring of chemicals in the brain can assist in understanding the working mechanism of the brain and exploring therapeutics for nerve disorders. Organic electrochemical transistors (OECTs) are employed for this purpose due to their high sensitivity from the in situ amplification effect. However, the chronic and stable detection of chemicals in the brain is rarely reported for OECTs. It is possibly due to the chronic inflammation from mechanical mismatch between the device and soft brain tissue as well as the biofouling that hinder the diffusion of chemicals to decrease the sensitivity similar to other implanted devices. Therefore, an all‐polymer fiber OECT (PF‐OECT) is designed, composed solely of conductive polymers and fluorine rubber. The PF‐OECT shows matching modulus with the soft brain tissue and good anti‐biofouling performance. It also demonstrates both high sensitivity and electrochemical stability under dynamic deformations and in complex protein solutions. Finally, the PF‐OECT is implanted into the mouse brain, achieving a stable 14‐day ascorbic acid monitoring. The design strategy of PF‐OECT presents a potential avenue for developing more biomedical devices.

High performing supercapacitors using Cr2O3 nanostructures with stable channels- theoretical and experimental insights

Cr2O3 is considered to be a promising cathodic material for supercapacitor applications on the account of its fast redox kinetics, mesoporous structure, and high electrochemical stability. Using a one-step synthesis of Cr2O3, a unique cactus-like morphology can be easily obtained. Such particles improve the specific surface area and electrolyte ion diffusion, leading to enhanced capacitance values. The prepared cactus-like (Cr2O3-c) particles are able to return a specific capacitance of 68 F/g at 5 mV s−1, in three-electrode measurement. This can be attributed to the redox couple of Cr4+/ Cr3+ displayed by Cr2O3 at the electrode–electrolyte interface. Further, the electrochemical performance of cactus-like Cr2O3 material (Cr2O3-c) and solid Cr2O3 spheres (Cr2O3-s) is also compared. This study proves that much superior performance is delivered by protruded nanoparticles. The spikes on the top of the particle surface ensures that two particles are well separated, which stimulates stable channels for ion intercalation–deintercalation. The physics can be explained using a modified free electron model for three-dimensional lattice. Further, using density functional theory (DFT) calculations the electronic band structure, density of states (DOS) and their influence on the electrochemical performance of Cr2O3 are evaluated.

Hierarchical Cu4SnS6 nanoflowers supported by MWCNT can accomplish everything: Supercapacitors, dye-sensitized solar cells and water splitting

An attempt has been made here to develop a novel 3D-like shape Cu4SnS6 flower with the support of MWCNT composite that can be used as an electrocatalyst for asymmetric supercapacitor, reduction of tri-iodide to iodide (I3−/I−) in DSSCs and overall water-splitting applications. Electrochemical findings show that Cu4SnS6/MWCNT electrode exhibits the best electrochemical performance, evidencing a high specific capacitance (755 F g−1 at 2 A g−1), outstanding rate capability and cycling stability (89% after 2000 cycles at 15 A g−1). The fabricated asymmetric supercapacitor i.e., Cu4SnS6/MWCNT//MWCNT displays an outstanding energy density of 87.81 W h kg−1 at an ultra-high-power density of 3600 W kg−1. It is found to be an effective electrocatalyst for the reduction of I3−/I− in DSSCs, notably the efficiency reached is 6.05% which is comparable to the typical Pt. In addition, the optimized Cu4SnS6/MWCNT catalyst demonstrates better oxygen and hydrogen evolution reaction, low overpotential, and high electrochemical stability. The results show that the Cu4SnS6/MWCNT hybrid is an efficient tetrafunctional electrocatalyst for future energy storage/generation/conversion devices.

A soft co-crystalline solid electrolyte for lithium-ion batteries.

Alternative solid electrolytes are the next key step in advancing lithium batteries with better thermal and chemical stability. A soft solid electrolyte, (Adpn)2LiPF6 (Adpn, adiponitrile), is synthesized and characterized that exhibits high thermal and electrochemical stability and good ionic conductivity, overcoming several limitations of conventional organic and ceramic materials. The surface of the electrolyte possesses a liquid nano-layer of Adpn that links grains for a facile ionic conduction without high pressure/temperature treatments. Further, the material can quickly self-heal if fractured and provides liquid-like conduction paths via the grain boundaries. A substantially high ion conductivity (~10-4 S cm-1) and lithium-ion transference number (0.54) are obtained due to weak interactions between 'hard' (charge dense) Li+ ions and the 'soft' (electronically polarizable) -C≡N group of Adpn. Molecular simulations predict that Li+ ions migrate at the co-crystal grain boundaries with a (preferentially) lower activation energy Ea and within the interstitial regions between the co-crystals with higher Ea values, where the bulk conductivity is a smaller but extant contribution. These co-crystals establish a special concept of crystal design to increase the thermal stability of LiPF6 by separating ions in the Adpn solvent matrix, and also exhibit a unique mechanism of ion conduction via low-resistance grain boundaries, which contrasts with ceramics or gel electrolytes.

Enabling high ionic conductivity in yttrium-based lithium halide electrolytes by composition modulation for all-solid-state batteries

Chloride electrolytes have again become a focus of research in recent years due to the oxidative stability at high potential. Y-based chlorides such as Li3YCl6 have a considerable ionic conductivity of ∼10−4 S/cm. The ionic conductivity of a solid-state electrolyte (SSE) is closely related to its crystal structure. Low lithium concentration composition is beneficial for lithium-ion conduction structure. Due to the presence of more free octahedral sites, the crystal structure with Pnma space group has a better ion diffusion compared to the crystal structure with P-3m1 space group with hexagonal close-packed structure (hcp). In addition to this, the doping of cations with higher valence states results in more lithium vacancy compensation in the crystal structure, which is a significant modification to improve the ionic conductivity of the chloride. Herein, ab initio molecular dynamics (AIMD) simulations were performed to investigate the effects of the lithium-deficient state configuration and the cation Nb5+ doping modification on the ion conduction of LiaYClb solid-state electrolytes. The lithium-deficient state composition structure has shifted the material space group structure from P-3m1 to Pnma, which facilitates the diffusion of lithium ions. The Nb5+ doping has increased the chance of lithium ion co-diffusion and disordered the lithium ion sites near the Y(Nb) cation site, resulting in a lower ab-plane diffusion barrier and a significant improvement of lithium ion migration. A series of lithium-deficient state compositions and Nb-doped chlorides were synthesized. Li2.31Y0.98Nb0.02Cl5.31 is obtained by solid sintering preparation with an ionic conductivity close to 1.0 × 10−3 S/cm and high electrochemical stability. The full cell of Li2.31Y0.98Nb0.02Cl5.31 matched with bare LiCoO2 maintains stability for 100 cycles.

Bifunctional electrocatalytic water splitting augmented by cobalt-nickel-ferrite NPs-supported fluoride-free MXene as a novel electrocatalyst

Electrocatalytic water splitting is a promising approach for the massive production of hydrogen as an environmentally compatible and renewable energy alternative to fossil fuels. The development of an active, stable, low-cost, and bifunctional electrocatalyst, in this regard, is a big challenge to achieve the desired electrocatalytic hydrogen/oxygen production via water splitting. MXene (Ti3C2Tx) has recently been explored as an excellent candidate for electrocatalytic water splitting. However, its poor stability, hazardous synthesis routes, and the restacking of its flakes are the major bottlenecks in its effective application as an electrocatalyst. Herein, we adopted an acid-free wet chemical approach to synthesize MXene and its composites with CoNiFe2O4 for efficient water splitting. We proposed a novel layer-by-layer (LBL) assembly approach to obtain a CoNiFe2O4/MXene-based 2D/NPs/2D network and prevented restacking in MXene flakes for efficient electrocatalysis. The inserted NPs via the LBL approach engaged the delaminated MXene flakes, which results in a high surface area and active sites for water splitting. The fabricated catalyst showed excellent overpotentials of 149 and 17 mV at 10 mA/cm2 for water splitting via OER and HER. In addition, the Tafel slope of 36 and 45 mV/dec was achieved for HER and OER along with high electrochemical stability upto 100 h, which surpassed many similar catalysts that were recently reported in the literature. This study provides insights into the design of multicomponent low-dimensionalelectrocatalysts for water splitting.

Boron nitride as an “all-in-one” gelator to immobilize concentrated sulfone electrolyte towards high performance lithium metal batteries

Quasi-solid-state electrolytes obtained by gelation of liquid electrolytes are promising for use in high-safety and high-energy-density Li metal batteries (LMBs). However, the efficient development of a solid–electrolyte interface (SEI) and suppression of Al corrosion through the rational design of a gelator and liquid electrolyte remains challenging for gel electrolytes. Herein, a concentrated sulfone electrolyte possessing Li+ hopping conduction was immobilized with boron nitride (BN) as an “all-in-one” gelator via simple grinding. This method produced a BN-gel with high electrochemical stability, nonflammability, Li+conductivity, and modulus in a wide temperature range. The desolvation energy and diffusion barrier of Li+ was reduced in BN-gel, which resulted in an abundant release of “free” Li+ ions for fast ion transport. BN-gel suppresses Al corrosion and promotes the formation of a robust SEI that efficiently protects the current collector and prevents Li dendrite growth. The multifunctional merits of BN-gels endow LMBs based on LiFePO4 (LFP) and high-voltage Li(Ni0.8Co0.1Mn0.1)O2 (NCM) cathodes with excellent battery performance at room and high temperatures.

Highly robust and flexible micro-supercapacitors based on medium-entropy carbide nanowires toward sub-ambient temperature operation

Currently, the exploration of energy conversion/storage devices for harsh environment applications with satisfying property is still a grand challenge. In the present work, the highly robust and flexible micro-supercapacitors (MSCs) based on (Ta, Ti, Nb)C nanowires (NWs) and activated carbon hybrid structures as the electrode materials are reported. Given to the inherent advantages of (Ta, Ti, Nb)C NWs, e.g. stable electrical conductivity and mechanical flexibility, and abundant porous structure stemed from cross-linked (Ta, Ti, Nb)C NWs and bamboo-based active carbon, the as-prepared (Ta, Ti, Nb)C/C-MSCs show high electrochemical performance, mechanical stability, and temperature tolerance over a wide temperature range. Remarkably, the as-constructed (Ta, Ti, Nb)C/C-MSCs can endure the sub-ambient temperature operation down to −50 °C with a capacitance retention of 82.7% and present capacitance retention up to 97.7% over one cycle of cooling and heating between −50 and 25 °C, compared with that at room temperature. Even under progressive variation in temperatures ranged between 25 and -50 °C, the capacitance retention keeps up to 92.6% over 9000 cycles, representing their promising to be serviced as highly robust MSCs against harsh low-temperature conditions for energy storage.

Boosting electrocatalytic performance and durability of Pt nanoparticles by conductive MO2−x (M = Ti, Zr) supports

Metal oxides, especially TiO2, have been studied as an alternative support to replace the carbon in the conventional Pt/C catalysts for their high electrochemical stability at high electrode potentials. The low conductivity of metal oxides has been a big hurdle. In this work, we successfully overcome this issue by forming conductive MO2−x (M = Ti and Zr) through solid state reduction with NaBH4. The temperature of the reaction has turned out to be a crucial parameter to obtain highly conductive MO2−x. Pt/MO2−x catalysts were prepared by depositing Pt nanoparticles (NPs) on MO2−x supports whose analysis data, show that the Pt NPs are uniformly deposited on the surface of MO2−x supports and that there is a strong electronic interaction between Pt NPs and MO2−x supports. The electrocatalysis of Pt/MO2−x catalysts for oxygen reduction reaction (ORR) has been studied. Pt/MO2−x catalysts show significantly enhanced mass activity (MA) and specific activity (SA) from those of Pt/C catalyst. More importantly, Pt/MO2−x catalysts show a superior long-term durability. After 50,000 cycles of durability test, Pt/T370 catalyst retains 75%/84% of initial MA/SA, and Pt/Z438 catalyst retains 81%/88% of initial MA/SA, while Pt/C catalyst keeps only 36%/56% of initial MA/SA after 30,000 cycles. The significantly enhanced ORR performance of Pt/MO2−x catalysts is attributed to the strong metal-support interaction (SMSI) effect between MO2−x and Pt NPs as well as the high conductivity of MO2−x supports. We believe Pt/MO2−x catalysts are a promising form of electrocatalysts that can replace the presently dominating but not quite satisfactory Pt/C in fuel cell applications.

A stretchable wireless wearable bioelectronic system for multiplexed monitoring and combination treatment of infected chronic wounds.

Chronic nonhealing wounds are one of the major and rapidly growing clinical complications all over the world. Current therapies frequently require emergent surgical interventions, while abuse and misapplication of therapeutic drugs often lead to an increased morbidity and mortality rate. Here, we introduce a wearable bioelectronic system that wirelessly and continuously monitors the physiological conditions of the wound bed via a custom-developed multiplexed multimodal electrochemical biosensor array and performs noninvasive combination therapy through controlled anti-inflammatory antimicrobial treatment and electrically stimulated tissue regeneration. The wearable patch is fully biocompatible, mechanically flexible, stretchable, and can conformally adhere to the skin wound throughout the entire healing process. Real-time metabolic and inflammatory monitoring in a series of preclinical in vivo experiments showed high accuracy and electrochemical stability of the wearable patch for multiplexed spatial and temporal wound biomarker analysis. The combination therapy enabled substantially accelerated cutaneous chronic wound healing in a rodent model.