Gel Electrolyte Research Articles

Designed inorganics doped gel electrolyte with enhancing ion transfer and diffusion effects for flexible interdigitated supercapacitors

Electrolyte enhancement strategy becomes a promising route to improve flexible interdigitated miniaturized supercapacitors (IMSCs) performance due to the less mass loading of electrode materials on interdigitated electrodes. Herein, we develop a flexible polyvinyl alcohol/KOH (PVA/KOH) gel electrolyte with homogeneous BN-PDA (polydopamine modified boron nitride nanosheets) doping for enhancing energy storage of IMSCs, in which the conductivity is up to 112.1 mS cm−1 with excellent mechanical strength and heat stability. The ionicity of BN-PDA caused by electronegativity difference between B and N atoms significantly facilitates KOH transfer in PVA gel and diffusion in electrode diffuse layer by rapping-pairing effect. Furthermore, the different phase transition behavior of BN-PDA and PVA in water provides additional ions transmission pathways and effectively disperses external forces. With such excellent electrolytes, ultra-high energy density (14.7 μWh cm−2) at a high power density (420 μW cm−2) has been achieved for IMSCs. Moreover, the capacitance of IMSCs can always be maintained at a very high level during the long-term charge and discharge process. Our work suggests a feasible pathway to design inorganic fillers uniformly modified gel electrolyte with high conductivity and increased energy storage capacity of IMSCs as well as other flexible energy storage devices.

A Review on Recent Advances and Perspectives in Hydrogel Polymer Electrolytes for Aqueous Zinc‐Ion Batteries

In comparison with solid polymer electrolytes, hydrogel polymer electrolytes are now a potentially suitable candidate for aqueous zinc‐ion batteries (ZIBs). Generally, a hydrogel is mainly composed of a hydrophilic polymer network with a high water absorption propensity and the distinctive properties of being soft and wet, becoming a gel and solid polymer electrolyte in terms of ionic conductivity and mechanical properties. All these unique characteristics of electrolytes combine with an appropriate anode and cathode materials to deliver high safety, low cost, environmental friendliness, and excellent electrochemical performance in ZIB. Nevertheless, there is no comprehensive overview on the development of hydrogel electrolytes for ZIBs available. Therefore, this study focuses on the most recent breakthroughs in hydrogel‐based polymer electrolytes for ZIBs. Further, a brief explanation of various types of hydrogel electrolytes as well as the electrochemical performance of different polymer‐based electrolytes arediscussed. Finally, the challenges of hydrogel electrolytes for currently established Zn‐ion batteries and the future research directions towards the high‐performance flexibile ZIBs are explored.

Self‐Healing Waterborne Polyurethanes as a Sustainable Gel Electrolyte for Flexible Electrochromic Devices

Self‐healing polymers are promising for diverse applications in wearable technology and electronic skin. Polyurethanes are versatile polymers that can incorporate various monomer structures. Waterborne polyurethanes (WPUs) emerge as an environmentally conscious choice due to water usage instead of organic solvents, thereby minimizing the generation of volatile organic compounds. This study introduces a novel approach to enhance the self‐healing properties of WPUs by integrating disulfide bonds. These dynamic disulfide bonds undergo exchange reactions upon heating, facilitating the renewal of cross‐links on damaged film surfaces. Self‐healing WPUs with a low glass transition temperature achieve excellent self‐healing efficiency under mild conditions. Self‐healing adhesives applied to various flexible substrates retain stable peel strength, which confirms their potential as self‐healing solutions. Furthermore, the WPU hydrogel electrolyte is prepared with dihydroxyhexyl viologen (DHHV), and the prepared electrochromic gel exhibits good ionic conductivity while maintaining high transparency. The flexible electrochromic device exhibited excellent performances, including low coloration voltage, high coloration efficiency, and long‐term stability. The transmittance difference is exceptional, with over 99%, and no decay after repeated bending cycles is observed. The current results demonstrate the feasibility of self‐healing WPUs in improving the operation and durability of high‐performance flexible electrochromic devices.

Gel polymer electrolytes based on compound cationic additives for environmentally adaptive flexible zinc-air batteries with a stable electrolyte/zinc anode interface

With the rapid development of flexible wearable technology, there is an urgent need for the exploitation of flexible and sustainable energy storage devices. Flexible zinc-air battery (ZABs) have attracted extensive attention from researchers due to their high theoretical energy density, abundant raw material and environmental friendliness. However, there is no more effective strategy to solve the problems of dendrite growth and by-products formation on the zinc anode surface of flexible ZABs in a strong alkaline environment. Herein, the PMA-HLx hydrogels based on chitosan quaternary ammonium salt (HACC) and La3+ as compound cationic additives are prepared as gel polymer electrolytes (GPEs) for flexible ZABs. The optimal PMA-HL0.02 GPE shows admirable interfacial adhesion and favorable ionic conductivity of 130.43 mS cm−1. Meanwhile, the assembled flexible ZAB exhibits excellent electrochemical performance and long cycle life, as well as a stable charge-discharge voltage gap at different bending angles, and still has favorable power densities of 113.2 mW cm−2 and 93.65 mW cm−2 at -20°C and 80°C, respectively. Therefore, this synthesis strategy of GPEs based on compound cationic additives provides a useful reference for the development of flexible ZABs with environmental adaptability and interfacial stability in alkaline electrolyte environment.

Highly conductive, mechanically robust and multi-purpose carbon aerogel composites derived from waste bread enable high-performance symmetric supercapacitors

Sustainable biomass-based carbon aerogels have attracted extensive concerns in the area of energy storage and wearable sensory electronics. However, the pristine porosity and low weight of aerogels result in unsatisfactory mechanical and electrical properties, limiting their practical applications. Herein, activated porous carbon (APC), reduced graphene oxide (rGO) and carbon nanoparticles (CNP) are utilized as raw materials to develop a novel type of hierarchically waste bread-derived carbon aerogel via a stepwise activation/calcination strategy. The obtained bread-derived carbon aerogels, named APC-rGO/CNP, exhibits an outstanding electrical conductivity (∼3.23 S cm−1) and a high compressive modulus (∼124.60 MPa) by the synergistic bonding interactions. As a supercapacitor electrode, the APC-rGO/CNP composite manifests an excellent capacitance of 474.8 F g−1 (1.0 A g−1). Furthermore, an all-solid-state symmetric APC-rGO/CNP//APC-rGO/CNP supercapacitor with polyvinyl alcohol/potassium hydroxide (PVA/KOH) gel electrolyte realizes an energy density of 17.4 Wh kg−1 at 895 W kg−1. Notably, even under large compressive stress of 20 kPa, the supercapacitor still achieves a high energy density of 25.6 Wh kg−1 at a power density of 822.8 W kg−1, as well as an excellent capacitance retention of 93.8 % over 10,000 cycles. Finally, we demonstrate the potential of the APC-rGO/CNP composite as a responsive pressure sensor with an ultra-wide detecting span of 0–3 MPa and a moderate sensitivity of 0.22 kPa−1, which can detect keyboard pressing and fist clenching movements distinctively. Overall, the desirable mechanical performances and electrical conductivity of the APC-rGO/CNP composites facilitate the development of versatile nanomaterials to exploit state-of-the-art wearable electronics.

Exploiting Mixed Valence Charge Transfer for Electrochromic and Electrofluorochromic Use.

An asymmetric mixed valence fluorophore with two different electron rich termini was investigated as a dual-role active material for electrochromism and electrofluorochromism. The fluorescence quantum yield (Φfl) and emission wavelength of the fluorophore were dependent on solvent polarity. The quantum yield of the material in an electrolyte gel, on a glass substrate and in a device was 40 %, 20 % and 13 % respectively. The fluorophore further underwent two near-simultaneous electrochemical oxidations. The first oxidation resulted in a 1000 nm red shift in the absorption to broadly absorb in the NIR, corresponding to the intervalence charge transfer (IVCT). Whereas the second oxidation led to a perceived green color at 715 nm with the extinction of the NIR absorbing IVCT. Owing to the dissymmetry of the fluorophore along with its two unique oxidation sites, the IVCT gives rise to a mixed valence transfer charge (MVCT). The coloration efficiency of the fluorophore in both solution and a device was 1433 and 200 cm2 C-1, respectively. The fluorescence intensity could be reversibly modulated electrochemically. The photoemission intensity of the fluorophore was modulated with applied potential in an operating electrochromic/electrofluorochromic device. Both the dual electrochromic and the electrofluorochromic behavior of the fluorophore were demonstrated.

Green Polymer Electrolytes Prepared by a Cost-Effective Approach.

The preparation of solid polymer electrolytes (SPEs) using poly(ethylene oxide) (PEO) typically involves incorporating fillers or undergoing chemical modifications to reduce crystallinity and enhance conductivity. PEO with a lower molecular weight, known as polyethylene glycol (PEG), exhibits higher conductivity, despite weaker mechanical strength. It is commonly employed as a plasticizer to improve the conductivity of SPEs or to fabricate PEG-based gel polymer electrolytes (GPEs). In this study, we use a straightforward approach to create innovative SPEs by blending liquid polymer electrolytes (LPEs), particularly low-molecular-weight polyethylene glycol (PEG), with a molecular weight of 400 g/mol, and sustainable poly(l-lactide) (PLLA). Solid PEG/PLLA forms are achieved by introducing 30 wt % of PLLA. Subsequently, the addition of lithium salts results in the development of novel PEG/PLLA SPEs. Another focal point of this study involves incorporating 1,3:2,4-dibenzylidene sorbitol (DBS) into these PEG/PLLA systems. DBS, an organic gelator derived from natural sugars, demonstrates self-assembly, leading to the formation of a nanofibrillar network structure. Leveraging DBS's ability to form organogels in liquid organic environments, we facilitate the transformation of low PLLA content LPEs into innovative solvent-free GPEs. Our prepared PEG/PLLA SPEs exhibited a maximum conductivity value of 4.39 × 10-5 S/cm, approximately five times higher than that of neat PEG (10000 g/mol) SPEs. The ionic conductivity exhibited a declining trend as the content of PLLA and DBS increased. However, there was an improvement in electrochemical stability. Furthermore, the incorporation of PLLA and DBS into electrolytes contributed to enhanced mechanical support and stability within the electrolyte layer. This, in turn, mitigated capacity decay and improved the cycling performance of assembled lithium-ion cells.

The nanofiber gel electrolytes with ultra-high ionic conductivity regulated by different acid radical ions for lithium batteries

A nanofiber gel electrolytes with excellent physical properties, electrochemical properties, and cycle life based on poly(vinylidene fluoride)-hexafluoropropylene copolymer modified by magnesium–aluminum bilayered nanosheets (MgAl-LDs) intercalated with different acidic roots ions is prepared by electrostatic spinning. The electrolytes exhibit the best elongation at break of 166 % and tensile strength of 6.59 MPa, and the electrochemical windows are all higher than 5 V. Meanwhile, the ionic conductivity number of nano-GPE intercalated with CO32–, ClO4−, and NO3– reach 5.55*10−3 S/cm, 5.04*10−3 S/cm, and 6.93*10−3 S/cm, respectively. The Li//Li symmetric battery can be stably cycled for more than 1000 h at 1 mA/cm2 with an overpotential of less than 50 mV. The LiFePO4// Li batteries assembled with nano-GPE modified by MgAl-LDs (s = NO3–) show better 0.1-2C multiplicity performance than CO32– and ClO4−, accompanied by an optimal discharge capacity of up to 155 mAhg−1 at 0.1C as well as a high reversible capacity of 135 mAhg−1 and a capacity retention rate of 90 % after 100 cycles at 0.5C. In addition, the results of polarization, X-ray photoelectron spectroscopy (XPS), Computed Tomography (CT), and scanning electron microscope (SEM) tests show that a stable SEI film is formed between nano-GPE and Li anode.

Three‐Dimensional Porous Spongy Ti3C2Tx MXene/Polyvinyl Alcohol/Agar Gel Electrolyte with High Ionic Conductivity Enables Highly Reversible Zinc‐Ion Batteries

Gel electrolyte is one of the key components of flexible energy storage devices. The construction of a three‐dimensional (3D) porous gel electrolyte with high ionic conductivity is a very effective strategy to improve the performance of zinc‐ion batteries (ZIBs). Herein, porous polyvinyl alcohol‐Agar‐sodium dodecyl sulfate‐MXene‐dimethyl sulfoxide (DMSO) (denoted as PVA‐Agar‐SDS‐MXene‐DMSO (PASMD)) gel electrolyte with double network is prepared through one‐pot method by adding two‐dimensional (2D) MXene to improve its ionic conductivity and DMSO to increase its low‐temperature resistance. Meanwhile, the as‐prepared PASMD gel electrolyte with a high ionic conductivity of 50.63 mS cm−1 realizes the gradient induction and redistribution of Zn2+, which drives oriented Zn (002) plane deposition of Zn2+ and then achieves uniform Zn deposition and dendrite‐free anode. The specific capacity of the assembled flexible Zn//PASMD//β‐MnO2 battery can reach 205 mAh g−1 at 0.2 A g−1. It also exhibits good performance both at room temperature and −20 °C with stable cyclic stability for more than 1000 h. After 1000 cycles at 1 A g−1, the assembled flexible battery stabilizes at 67 mAh g−1. This work provides an alternative pathway for the development of high‐performance gel electrolytes with low‐temperature resistance and high‐ionic conductivity for flexible ZIBs.

Favored Amorphous LixSi Process with Restrained Volume Change Enabling Long Cycling Quasi-Solid-State SiOx anode.

Silicon-based anodes are becoming promising materials due to their high specific capacity. However, the intrinsically large volume change brought about by the alloying reaction results in the crushing of the active particles and destruction of the electrode structure, which severely limits its practical application. Various structured and modified silica-based anodes exhibit improved cycling stability and the demonstrated ability to mitigate their volume changes through interfacial and binder strategies. However, the issue of large volume changes in silicon-based anodes remains. Herein, we report a gel polymer electrolyte (GPE) prepared through an in situ thermal polymerization process that is suitable for SiOx anode materials and achieving long-term cycling stability. GPE-based cells essentially mitigate the volume change of SiOx anodes by guiding the unique lithiation/delithiation mechanism that tends to favor the formation and delithiation of amorphous-LixSi (a-LixSi) with smaller volume change, thereby mitigating electrode damage and cracking, and achieving the significant improvement in cycling performance. The prepared GPE-SiOx cells retained 693.80 mAh g-1 reversible capacity after 450 cycles at 500 mA g-1. In addition, the prelithiation process was incorporated to mitigate capacity fluctuations and improve the Initial Coulombic Efficiency (ICE), and a reversible capacity of 641.90 mAh g-1 was retained after 480 cycles.

The Possible Mechanism of Improving the Performance of Lead‐Acid Batteries by Using Aluminum Ions to Influence the Gel Structure

Gel lead‐acid batteries have the advantages of no acid leakage, no maintenance, and a long cycle life. In this article, it was found that Al3+ in the gel electrolyte can shorten the gel time and improve the stability of the gel. The battery test results show that the HRPSoC cycle life of the gel battery can be significantly improved by adding Al3+. In comparison to blank gel batteries without Al3+, HRPSoC cycle life is 8.2 times higher. Additionally, the gel battery with added Al3+ has a 0.5C discharge capacity of 1.8 Ah, which is 2.5 times that of the blank gel battery. The added Al3+ also demonstrates good capacity stability and still retains a capacity of 1.7 Ah after 150 discharge cycles. The kinetic simulation shows that Al3+ may participate in the formation of a silicon gel system and tend to gather around Si atoms to affect the properties of the gel electrolyte.

High-Performance All-Solid-State on-Chip Planar Micro-Supercapacitors Based on Aminated Graphene Quantum Dots by Photolithography

Rapid development of portable miniaturized electronic devices has put forward higher requirements for microenergy. Functionalized graphene quantum dots combine the properties of both functionalized graphene and quantum dots, and are expected to promote further development of high-performance energy storage devices. Here, all-solid-state on-chip planar micro-supercapacitors (PMSCs) were fabricated based on aminated graphene quantum dots by modified liquid-gas interface self-assembly and photolithography, with the electrode width/gap of 24 μm/8 μm. The electrochemical performance was analyzed by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), electrochemical impedance spectrometry and cycle stability in PVA/H2SO4 gel electrolyte. The results indicated that the fabricated PMSCs showed good capacitive response at the scan rates of 0.01 V s−1 to 10000 V s−1. The CV curves of the PMSCs displayed a typical pseudocapacitive feature at the scan rates of 0.01 V s−1 to 1 V s−1. The PMSCs had ultrahigh rate capability of up to 10000 V s−1, and the GCD curves were near triangle-shaped curves, demonstrating excellent electrochemical reversibility. The PMSCs showed ideal capacitive behavior at the low frequency region of the Nyquist plot. The Nyquist plot of the PMSCs showed a semicircle at the high frequency region. The relaxation time constant of the PMSCs were 3.59 μs, indicating that the PMSCs had fast frequency response. After 10000 charge-discharge cycles at the scan rate of 500 V s−1, the initial capacitance retention rate of the PMSCs were 99.17%, indicating that the PMSCs possessed good long-term electrochemical stability. This study provides an important reference for the application of functional graphene quantum dots in the field of the PMSCs.

Effect of introducing different molecular liquid solvents on electrochemical and physical properties of sodium ion conducting polymer gel electrolytes

The current investigation presents comparative studies on the effect of introducing three different molecular liquid solvents, namely ethylene carbonate: diethyl carbonate (EC:DEC), tetra ethylene glycol dimethyl ether (TEGDME), and 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIM-BF4) on the electrochemical and physical properties of sodium ion conducting polymer gel electrolytes (PGEs) containing sodium tetrafluoroborate (NaBF4) salt, and polyvinyllidene fluoride-co-hexafluoropropylene (PVdF-HFP) polymer. The PGE, which is optimized and contains the EC: DEC solvent, has an ionic conductivity of 8.9 × 10−4 S cm−1, electrochemical stability of 4.5 V and total ion transport number of 0.99 at 30 °C. Along with conductivity studies, the X-ray diffraction studies, show that the EC: DEC raises the entropy of the PGE to its maximum value. The thermogravimetric (TGA) and differential scanning calorimetry (DSC) investigations demonstrate that electrolyte with EC: DEC exhibits a weight loss of 13 % up to 200 °C and retain the gel phase up to 140 °C. The optimized electrolyte holds promise for forthcoming sodium based electrochemical devices.

Egg White─a Polymer Gel Electrolyte with Exceptionally High Ionic Conductivity

Egg White─a Polymer Gel Electrolyte with Exceptionally High Ionic Conductivity

Self-assembled 3D CoSe-based sulfur host enables high-efficient and durable electrocatalytic conversion of polysulfides for flexible lithium-sulfur batteries

Lithium-sulfur (Li-S) batteries are considered as promising candidates for next-generation energy storage systems. However, the commercial applications are severely limited by the sluggish kinetics and shuttling effect. Herein, we have designed an integrated free-standing functional CoSe-CNF-GO-MXene (CCGM) sulfur host with a “point-line-plane” 3D porous structure for Li-S batteries. The two-dimensional (2D) graphene, MXene and one-dimensional (1D) nanocellulose fibers combined with zero-dimensional (0D) transition metal selenide (CoSe) shows good electrical conductivity and enhanced catalytic performance, respectively. Additionally, the rationally designed porous structure (from 0D to 3D) demonstrates well-connected ion/electron transport channels, conferring the good kinetic performance. Electrochemical tests show that CoSe catalytic materials with moderate adsorption energies can catalyse both precipitation and dissolution processes of Li2S, enabling fast conversion kinetics. The density functional theory (DFT) calculations show that the synergistic effect of CoSe, Ti3C2Tx, and graphene can improve the chemisorption and catalytic performance. As a result, the 3D porous S@CCGM cathode exhibits a high initial discharge capacity of 1205.1 mAh g−1 at 0.2C and good long-term cycling performance with a low decay rate of 0.055 % per cycle at 1C. Furthermore, the gel electrolyte Li-S pouch cell successfully passes the 0–180° bending test, nailing test, and cutting test. Such design offers a new perspective for the commercialization of safe and flexible electrochemical energy-storage devices especially in Li-S batteries.

Highly Tough Slide-Crosslinked Gel Polymer Electrolyte for Stable Lithium Metal Batteries.

Gel polymer electrolytes (GPEs) hold great promise for the practical application of lithium metal batteries. However, conventional GPEs hardly resists lithium dendrites growth and maintains long-term cycling stability of the battery due to its poor mechanical performance. Inspired by the slide-ring structure of polyrotaxanes (PRs), herein we developed a dynamic slide-crosslinked gel polymer electrolyte (SCGPE) with extraordinary stretchability of 970.93 % and mechanical strength of 1.15 MPa, which is helpful to buffer the volume change of electrodes and maintain mechanical integrity of the battery structure during cycling. Notably, the PRs structures can provide fast ion transport channels to obtain high ionic conductivity of 1.73×10-3 S cm-1 at 30 °C. Additionally, the strong polar groups in SCGPE restrict the free movement of anions to achieve high lithium-ion transference number of 0.71, which is favorable to enhance Li+ transport dynamics and induce uniform Li+ deposition. Benefiting from these features, the constructed Li|SCGPE-3|LFP cells exhibit ultra-long and stable cycle life over 1000 cycles and high-capacity retention (89.6 % after 1000 cycles). Even at a high rate of 16 C, the cells deliver a high capacity of 79.2 mAh g-1. The slide-crosslinking strategy in this work provides a new perspective on the design of advanced GPEs for LMBs.

In Operando Study of Microsupercapacitors with Gel Electrolytes Using Nano‐Beam Synchrotron X‐ray Diffraction

AbstractSynchrotron radiation X‐ray diffraction (XRD) with nanoscale beam size was used here for in situ and in operando study of micro‐supercapacitors (MSC) with gel electrolyte and MXene Ti3C2Tx electrodes. The electrode structure was characterized as a function of applied voltage and distance from the gap separating electrodes using microscopic cells with cylindrical shape designed for transmission mode XRD. The devices with gel electrolytes based on H2SO4 (with H2O/PVA and DMSO/PVA) showed stable performance with no changes in MXene structure under voltage swaps between positive and negative values. Experiments with KI‐based electrolytes demonstrated changes of MXene structure correlated with decrease of energy storage parameters under conditions of increased operation voltage starting from 0.8 V. The optimal performance of the MSCs was observed when the MXene structure remained unchanged upon switching the applied voltage polarity. The changes of inter‐layer distance of MXene upon swap of applied voltage correlate with decrease of device performance and are undesirable for stable operation of MSC's. We also tested feasibility of X‐ray fluorescence (XRF) for characterization of electrolyte ion migration in MSCs using 2D element mapping. Irreversible sorption of iodine by MXene was found using XRF mapping of charged electrodes using standard in‐plane MSC device and KI electrolyte.

A gel polymer electrolyte obtained from cellulose acetate/polyvinylidene fluoride composite electrospun membrane for safe lithium metal batteries with high-rate capability

Li metal battery is a promising next-generation power storage devices, but faces the serious safety issues caused by the uncontrolled Li dendrite growth and leakage of the flammable organic electrolyte. Herein, a low-cost CA/PVDF (cellulose acetate/polyvinylidene fluoride) composite membrane is prepared via electrospinning technology for safe lithium metal batteries. This membrane (45 μm) exhibits the high porosity (76.9 %) and excellent thermally stability (>180 °C) preventing the short circuit during abuse. The CA/PVDF-based gel polymer electrolyte (GPE), fabricated with CA/PVDF electrospun membrane swelled by carbonate-based organic liquid electrolyte, delivers the ionic conductivity of 1.82 mS cm−1 and Li + transfer number of 0.506, which achieve uniform Li+ ion electrodeposition and inhibit the formation of lithium dendrites. As the results, the symmetrical cell Li/CA/PVDF-based GPE/Li exhibits the impressive reversible Li stripping/plating behavior over 300 h at 1 mA cm−2 with the capacity of 1 mA h cm−2. Furthermore, the assembled LiFePO4/GPE/Li battery exhibits the capacity of 101.2 mA h g−1 at 5C with the capacity retention of 94.6 % after 400 cycles, which exceeds that of traditional liquid electrolytes. This research provides a low-cost gel polymer electrolyte via the electrospinning technique for rechargeable lithium batteries with good electrochemical performance and high security.

Stereoscopic Imaging of Single Molecules at Plasma Membrane of Single Cell Using Photoreduction-Assisted Electrochemistry.

Stereoscopic imaging of single molecules at the plasma membrane of single cell requires spatial resolutions in 3 dimensions (x-y-z) at 10-nm level, which is rarely achieved using most optical super-resolution microscopies. Here, electrochemical stereoscopic microscopy with a detection limit down to a single molecule is achieved using a photoreduction-assisted cycle inside a 20-nm gel electrolyte nanoball at the tip of a nanopipette. On the basis of the electrochemical oxidation of Ru(bpy)3 2+ into Ru(bpy)3 3+ followed by the reduction of Ru(bpy)3 3+ into Ru(bpy)3 2+ by photogenerated isopropanol radicals, a charge of 1.5 fC is obtained from the cycling electron transfers involving one Ru(bpy)3 2+/3+ molecule. By using the nanopipette to scan the cellular membrane modified with Ru(bpy)3 2+-tagged antibody, the morphology of the cell membrane and the distribution of carcinoembryonic antigen (CEA) on the membrane are electrochemically visualized with a spatial resolution of 14 nm. The resultant stereoscopic image reveals more CEA on membrane protrusions, providing direct evidence to support easy access of membrane CEA to intravenous antibodies. The breakthrough in single-molecule electrochemistry at the cellular level leads to the establishment of high-resolution 3-dimensional single-cell electrochemical microscopy, offering an alternative strategy to remedy the imperfection of stereoscopic visualization in optical microscopes.

Gel electrolyte based high-performance fiber battery

Gel electrolyte based high-performance fiber battery