Scalable, microwave-assisted decoration of commercial cotton fabrics with binary nickel cobalt sulfides towards textile-based energy storage

Supercapacitor-powered wearable biosensor for continuous lactate monitoring from sweat

The development of wearable sensing platforms for continuous monitoring of sweat biomarkers has gained significant attention, particularly for lactate detection. This study presents the design and fabrication of a novel wearable lactate biosensor that integrates a flexible supercapacitor power supply with an advanced lactate sensing platform. The sensing platform features NiCo nanosheets electrodeposited onto nanocages of bimetallic CoFe Prussian Blue analogue (PBA), providing an optimal microenvironment for the immobilization of lactate oxidase (LOx) enzymes. The CoFe PBA nanocages act as efficient electrocatalysts for the reduction of hydrogen peroxide, enhancing the sensor's performance. The electrode exhibits a sensitivity of 262 μA mM-1cm-2 and demonstrates a short response time (<5 s), making it suitable for real-time monitoring applications. Additionally, the energy supply unit is constructed using a wearable conductive carbon textile (CCT) substrate modified with NiCoS through electrochemical deposition, achieving the necessary electrical conductivity. A flexible asymmetric supercapacitor (ASC) is then developed utilizing NiCoS@CCT and FeS@CNT@CCT as the positive and negative electrodes, respectively. This ASC exhibits remarkable electrochemical properties, including a high specific capacitance of 205 F g⁻1, notable energy density at elevated power densities, and excellent rate capability. Integrating these components with a custom-designed electronic circuit board results in a lightweight wearable sensor capable of continuous lactate monitoring in perspiration. This innovative approach demonstrates significant potential for advancing point-of-care health monitoring technologies.

Controlled establishment of advanced local high-entropy NiCoMnFe-based layered double hydroxide for zinc batteries and low-temperature supercapacitors

The development of high-performance electrodes is essential for improving the charge storage performance of rechargeable devices. In this study, local high-entropy C, N co-doped NiCoMnFe-based layered double hydroxide (C/N-NiCoMnFe-LDH, C/N-NCMF) were designed using a novel method. Multi-component synergistic effects can dramatically modulate the surface electron density, crystalline structure, and band-gap of the electrode. Thus, the electrical conductivity, electron transfer, and affinity for the electrolyte can be optimized. Additionally, the C/N-NCMF yielded a high specific capacitance (1454F·g-1) at 1 A·g-1. The electrode also exhibited excellent cycling stability, with 62 % capacitance retention after 5000 cycles. Moreover, the assembled Zn||C/N-NCMF battery and the C/N-NCMF//AC hybrid supercapacitor yielded excellent energy densities of 63.1 and 35.4 Wh·kg-1 at power densities of 1000 and 825 W·kg-1, and superior cycling performance with 69 % and 88.7 % capacitance retention after 1000 and 30,000 cycles, respectively. Furthermore, the electrode maintained high electrochemical activity and stability and ensured high energy density, power density, and cycling stability of the rechargeable devices even at a low temperature (-20 °C). This study paves a new pathway for regulating the electrochemical performance of LDH-based electrodes.

Mushroom-like cobalt nickle metaphosphate@nickel diselenide core-shell nanorods for asymmetric supercapacitors

Although transition metal metaphosphates (TMPOs) display special physical/chemical features and high theoretical capacities, their applications for supercapacitors (SCs) are still restricted by their low energy densities and inferior cycling stability. Herein, a novel strategy has been proposed to address these issues through in situ construction of cobalt nickle metaphosphate (Co_0.2Ni_0.8(PO₃)₂)@nickel diselenide (NiSe₂) core-shell heterostructure on carbon paper (CP) as a self-supporting flexible electrode for SCs. Particularly, this unique mushroom-like porous nanoarchitecture assembled by one-dimensional (1D) Co_0.2Ni_0.8(PO₃)₂ nanorods and zero-dimensional (0D) NiSe₂ nanospheres can expose abundant active sites and afford multi-dimensional channels, which favors rapid electron ions/electron transfer, accelerates the reaction kinetics, and alleviates volume changes during charging/discharging processes. Profiting from its well-aligned 1D/0D nanostructure and strong synergistic effect between Co_0.2Ni_0.8(PO₃)₂ and NiSe₂, the Co_0.2Ni_0.8(PO₃)₂@NiSe₂/CP electrode delivers a specific capacity of 219.4 mAh/g/0.414 mAh cm^-2 at 1 A/g and good cycling stability with capacity retention of 90.7% after 5000 cycles, outperforming many previously reported TMPO-based electrodes in literature. Impressively, an asymmetric supercapacitor (ASC) device assembled with Co_0.2Ni_0.8(PO₃)₂@NiSe₂ as cathode and porous carbon as anode achieves an energy density of 69.2 Wh kg^-1 at 736.0 W kg^-1 and maintains a capacity retention of 97.6% after 20,000 charge-discharge cycles. This work provides an efficient approach to design multi-dimensional hybrid nanomaterials for high-performance SCs.

Direct decoration of commercial cotton fabrics by binary nickel-cobalt metal-organic frameworks for flexible glucose sensing in next-generation wearable sensors

Having a prime significance in diagonsing and predicting the dangerous symptoms of chronic diseases in the early stages, special attention has been drawn by wearable glucose-sensing platforms in recent years. Herein, modified commercial cotton fabrics, decorated with binary Ni-Co metal-organic frameworks (NC-MOFs) through a one-pot scalable hydrothermal route, were directly utilized as flexible electrodes for non-enzymatic glucose amperometric sensing. Glucose sensitivities of 105.2 μA mM^-1 cm^-2 and 23 μA mM^-1 cm^-2 were acheived within two distinct linear dynamic ranges of 0.04-3.13 mM and 3.63-8.28 mM, respectively. Receiving benefits from a remarkable glucose sensitivity behavior in co-existence of iso-structures and interferences, rapid response (4.2 s), and remarkable reproducibility and repeatability, NC-MOF-modified cotton fabric electrodes are imensilly promising for developing high-performance wearable glucose sensing platfroms. The sensing performance of fabricated electrodes was further investigated in human blood serum and saliva.