Fiber-shaped Energy Storage Research Articles

A synchronous-twisting method to realize radial scalability in fibrous energy storage devices.

For wearable electronics, radial scalability is one of the key research areas for fibrous energy storage devices to be commercialized, but this field has been shelved for years due to the lack of effective methods and configuration arrangements. Here, the team presents a generalizable strategy to realize radial scalability by applying a synchronous-twisting method (STM) for synthesizing a coaxial-extensible configuration (CEC). As examples, aqueous fiber-shaped Zn-MnO2 batteries and MoS2-MnO2 supercapacitors with a diameter of ~500 μm and a length of 100 cm were made. Because of the radial scalability, uniform current distribution, and stable binding force in CEC, the devices not only have high energy densities (~316 Wh liter-1 for Zn-MnO2 batteries and ~107 Wh liter-1 for MoS2-MnO2 supercapacitors) but also maintain a stable operational state in textiles when external bending and tensile forces were applied. The fabricating method together with the radial scalability of the devices provides a reference for future fiber-shaped energy storage devices.

Carboxylic multiwalled carbon nanotube aerogel-based macroscale fiber as a highly porous current collector

Carbon nanotube yarn is a potential substance for the fabrication of fiber-shaped energy storage devices owing to its lightweight, stiffness, and excellent electrical properties. However, it has a compact structure with a limited pore volume, leading to insufficient active material loading and inadequate gel electrolyte penetration. These seriously restrict its application in fiber-shaped energy storage devices made entirely of solid-state components. Herein, glycerol-functionalized polyacrylonitrile nanofibers (GPN) are electro-spun and collected on Ti wire. And they are chosen as hydrophilic support to load carboxylic multiwalled carbon nanotubes (CMWCNTs) via dip-coating. After oxidation, a 3D rolled O-CMWCNTs@GPN/Ti aerogel fiber-shaped structure with macroscopic thickness and excellent stability in water is fabricated. The O-CMWCNTs@GPN/Ti structure has a high length-specific capacitance value of 15.2 mF cm−1 itself. It also can be used as a current collector to load pseudocapacitive materials to improve capacity. With polyaniline (PANI) electrodeposited in this structure, the as-prepared hybrid aerogel electrode PANI@O-CMWCNTs@GPN/Ti displays a high specific capacitance of 52.6 mF cm−1 in a fiber-shaped supercapacitor device. All features suggest that O-CMWCNTs@GPN/Ti aerogel is an excellent candidate for flexible fiber-shaped energy storage devices.

Constructing metal-organic framework-derived carbon incorporated V2O5 nanowire-bundle arrays on carbon nanotube fiber as advanced cathodes for high-performance wearable zinc-ion batteries

Fiber-shaped energy storage devices with light weight, superflexibility, and weavability demonstrate promising prospects for application in wearable and portable electronics. Especially, fiber-shaped aqueous rechargeable zinc ion batteries (FARZIBs), which can facilitate the development of wearable electronic products owing to their high safety, low cost, environmental friendliness. Nevertheless, it is very challenging to achieve high rate capability, energy density, and cycling performance simultaneously for the FARZIBs. Herein, a high-performance FARZIB is created from vanadium-based metal-organic frameworks (MOFs) derived vanadic oxide (V2O5) nanowire-bundle arrays (NBAs) grown on highly conductive carbon nanotube fibers (CNTFs) directly as the binder-free cathode. Profiting from high specific area and porous structure of MOFs, as well as arrays structure and binder-free features, our as-assembled FARZIBs exhibited a high capacity of 0.71 mAh cm−2 at a current density of 2 mA cm−2, and demonstrated outstanding rate capability and prominent cycling performance. Moreover, the FARZIBs delivered an extremely high energy density of 215 mWh cm−3 at a power density of 600 mW cm−3. Therefore, our work brings new prospects for the next generation of wearable electronics.

3D Architecturing Strategy on the Utmost Carbon Nanotube Fiber for Ultra‐High Performance Fiber‐Shaped Supercapacitor (Adv. Funct. Mater. 28/2022)

3D Fiber Electrodes In article number 2113057, Hyeon Su Jeong, Nam Dong Kim, and co-workers present a 3D-architectured fiber-shaped energy storage device in which the structure is expressed in detail. This fiber consists of active material and vertically deposited graphene oxide on carbon nanotube fibers composed of uniaxially oriented carbon nanotube. This object can be integrated into clothing and power various wearable devices.

Kinetically boosted potassium ion storage capability of 1D K2Ti6O13 nanobelts by 3D porous carbon framework for fiber-shaped potassium ion capacitors

One dimensional (1D) fiber-shaped energy storage device demonstrates a great potential for the future power source textiles. However, delivering high energy/power densities and long cycle life is still the crucially electrochemical themes to meet the ever-stringent demands. Herein, we report a novel non-aqueous fiber-shaped potassium ion capacitors (PICs), in which 1D K2Ti6O13 nanobelts (KTO) interweaved with three-dimensional (3D) porous carbon framework was synthesized as anode materials. The low specific capacity and sluggish reaction kinetics of the bare KTO is boosted by the 3D porous carbon framework. Its hierarchical porosity and 3D structure impede the aggregation of the KTO, and favor the permeation of potassium ions in electrolyte. Its graphitic carbon improves the electrical conductivity of the KTO. Meanwhile, it also offers a suitable potassium ion storage capacity. These features enable KTO@3D-C with high specific capacity and rate performance. A single non-aqueous fiber-shaped PICs with a high working voltage up to 3.5 V can lead to maximum areal and volumetric energy densities of 12.1 μWh cm−2 and 1.9 m Wh cm−3, indicating apparent energy advantages over the ones with aqueous electrolyte and symmetric configuration. Our integratable and robust fiber-shaped PICs prototype demonstrates a great potential for future power source textiles.

Towards ultrahigh-energy-density flexible aqueous rechargeable Ni//Bi batteries: Free-standing hierarchical nanowire arrays core-shell heterostructures system

Fiber-shaped energy storage devices featuring characteristics of macroscopic one-dimension, light weight, super-flexibility, and weavability demonstrate promising prospects for a category of crucial fields such as portable and wearable electronics. Particularly, fiber-shaped aqueous rechargeable (FAR) Ni//Bi batteries can further promote the development of wearable electronics due to their characteristics of low cost, flat discharge plateau, and no dendrite growth. However, it is currently challenging to simultaneously achieve high energy and power densities, and safety, which has seriously restricted their promising applications. Herein, a new type of FAR Ni//Bi battery with extraordinary electrochemical performance is created from hierarchical core-shell heterostructured electrodes, where bismuth trioxide (Bi2O3) nanosheets (NSs) directly grown on the surface of titanium nitride (TiN) nanowire arrays (NWAs) act as the anode while nickel hydroxide (Ni(OH)2) NSs anchored on zinc doping cobalt-nickel-oxide (Zn-CoNiO2) NWAs surface act as the cathode. Our as-assembled FAR Ni//Bi battery demonstrates ultrahigh energy density of 314.96 mWh cm−3 and remarkable power density of 20.04 W cm−3 with 88.6% capacity retention after 5000 cycles, which significantly outperform most state-of-the-art FAR batteries. This study offers a comprehensive and efficient strategy to develop high-performance aqueous rechargeable batteries by designing hierarchical core-shell heterostructured electrodes.

A top-down cutting method for construction of high-performance fiber-shaped quasi-solid-state asymmetric supercapacitors

Fiber-shaped asymmetric supercapacitors (FSASCs) have great potential as a future wearable energy storage system because of good weavability, a wide operating voltage window, and high energy density. Conventional bottom-up construction methods for fiber supercapacitors are time-consuming or highly costly. This work proposes a novel facile top-down cutting method to construct FSASCs. FSASCs with desired sizes can be rapidly constructed and easily scaled up by cutting a thin-film supercapacitor into fiber-shaped devices. Serial and parallel FSASCs free of external wire connection were assembled by cutting stacked film supercapacitors and multiplying the cutting width, respectively. Besides, the as-prepared FSASCs exhibit superior comprehensive electrochemical performance, including a high volumetric capacitance of 14.7 F/cm3, a high energy density of 93.5 μWh/cm2, and excellent flexibility. The cutting method with advantages of high simplicity, low cost, and high efficiency may be a general construction method for fiber-shaped energy storage devices.

Microfluidic-architected core–shell flower-like δ-MnO2@graphene fibers for high energy-storage wearable supercapacitors

Wire-shaped supercapacitor is an ideal candidate for wearable energy-storage devices in future. However, complex preparation process and poor capacitance of electrode materials seriously limit practical applications. Herein, we investigated a controllable method to synthesize core–shell MnO2/graphene fibers (MnGFs), where sheath flower-like δ-MnO2 were in situ growth wrapped on graphene core via microfluidic-spinning techniques. The MnGFs possess excellent mechanical flexibility and can be repeatedly bent without damage. Moreover, a flexible wire-shaped supercapacitors (MGSCs) assembled by MnGFs is successfully manufactured and display high capacitance (164.2 F cm−3), prominent energy density (4.3 mWh cm−3), and brilliant cycling stability (93.6% retention over 10,000 cycles). These comprehensive properties of MGSCs are obtained from MnGFs with porous and well-aligned core–sheath structure, resulting in abundant electron transport channels and rich ion pseudo-capacitance. Based on these achievements, the synthesized MGSCs can be employed to light up LEDs and electronic timers. This microfluidic strategy offers an extended design approach of electrochemically active electrode materials and guides the development of wearable fiber-shaped energy storage devices.

A novel flexible wire-shaped supercapacitor with enhanced electrochemical performance based on hierarchical Co(OH)2@Ni(OH)2 decorated porous dendritic Ni film/Ni wire

Wire-shaped supercapacitors, a new class of energy storage devices, have recently received enormous attention advantages of miniature size, lightweight and high flexibility. However, most of the reported wire-shaped supercapacitors are still suffered from low specific capacitance and limited energy densities as well as the relatively poor electrochemical performance. In this research, Co(OH)2@Ni(OH)2 nanosheets were successfully synthesized on the 3D-Ni film-coated Ni wire (NW) by electrochemical methods. The electrochemical tests of Co(OH)2@Ni(OH)2/3D-Ni/NW electrode confirmed the outstanding supercapacitive behavior of nanostructures with excellent cycling stability. This behavior could be attributed to 3D network structure of Ni film and the nanosheets which allow facile electrolyte and electrons transportation. Detailed electrochemical characterization shows that the Co(OH)2@Ni(OH)2/3D-Ni/NW exhibits a high specific capacitance of 355.2 C g–1 at current density of 1 Ag–1 and excellent cycle performance (80.0% retention after 3000 CD cycles). Also, the maximum energy density of 27.24 W h kg–1 at the power density of 234.99 W kg–1 was measured. The obtained results reveal that the Co(OH)2@Ni(OH)2 core-shell can be a promising electroactive material for supercapacitors. This unique supercapacitor opens up a new path in the development of fiber-shaped energy storage apparatuses.

Superstructured α-Fe2O3 nanorods as novel binder-free anodes for high-performing fiber-shaped Ni/Fe battery

Fiber-shaped energy storage devices areindispensableparts of wearable and portable electronics. Aqueous rechargeable Ni/Fe battery is a very appropriate energy storage device due to their good safety without organic electrolytes, high ionic conductivity, and low cost. Unfortunately, the low energy density, poor power density and cycling performance hinder its further practical applications. In this study, in order to obtain high performance negative iron-based material, we first synthesized α-iron oxide (α-Fe2O3) nanorods (NRs) with superstructures on the surface of highly conductive carbon nanotube fibers (CNTFs), then electrically conductive polypyrrole (PPy) was coated to enhance the electron, ion diffusion and cycle stability. Theas-prepared α-Fe2O3@PPy NRs/CNTF electrode shows a high specific capacity of 0.62 Ah cm−3 at the current density of 1 A cm−3. Furthermore, the Ni/Fe battery that was assembled by the above negative electrode shows a maximum volumetric energy density of 15.47 mWh cm−3 with 228.2 mW cm−3 at a current density of 1 A cm−3. The cycling durability and mechanical flexibility of the Ni/Fe battery were tested, which show good prospect for practical application. In summary, these merits make it possible for our Ni/Fe battery to have practical applications in next generation flexible energy storage devices.

Quasi-solid-state fiber-shaped aqueous energy storage devices: recent advances and prospects

The on-going surge in wearable electronics has inspired ever-increasing rise in requirement for quasi-solid-state fiber-shaped energy storage devices, which possess 1D unique architecture with a tiny volume, and remarkable flexibility.

A Year of Deep Change and Transformation

This past year was transformative for Wiley but also a year of profound change for the Advanced family of journals with the departure of Professor Peter S. Gregory, long-standing Editor-in-Chief of Advanced Materials. It is appropriate to take this opportunity to reflect on Peter's deep contribution to Wiley-VCH: from a single journal, itself a spin-off of Angewandte Chemie, the Advanced family has grown into 16 branded journals and over 50 journals in the Materials Science and Physics program of Wiley. The program now covers all areas of Materials Science and extends to adjacent or burgeoning fields from Physics to Quantum Computing and Machine Learning. The latest addition to this family, Advanced Intelligent Systems, covers a field that did not even exist when Peter first took the helm of Advanced Materials. I join my colleagues here at Wiley-VCH in thanking Peter for all he has taught us over the years and congratulate him for the amazing legacy he leaves in our care. One overarching idea Peter almost always stressed is that scientific publishing is ultimately a people business and that a publisher can only be successful when it focuses its service on the researcher. The changes we commited to this past year are in service to this philosophy. Many in our community have long demanded a transition from a subscriptions-based model to the Open Access model of scientific publishing but it was never clear how to sustainably achieve such a transition. Wiley thinks it has found an answer and has committed to a transformative agreement with the projekt-DEAL consortium in Germany. This arrangement has given affiliated researchers access to the entire Wiley collection since January 2019. Open Access publishing fees are covered by MPDL-Services GmbH, either fully for hybrid journals or for at a deeply discounted rate for fully Open Access journals. This agreement has resulted in a vast expansion of access to the Wiley collection while simultaneously keeping costs under control. Comparable agreements are already in place in Hungary and the Netherlands, and more countries have expressed interest in similar “Publish and Read” arrangements. More is sure to come in the next few years. One other long-standing request of our communities is the possibility to earn recognition for one's review work. We're happy to have the ability to recognise and credit our reviewer through the ORCID Review Credit Deposit, a service managed through the ORCID architecture. To receive credit for reviews you will need an ORCID iD and will need to actively opt-in to this service when you submit your report. Your identity as a reviewer will be protected and no specific manuscripts or author details will be shown in your ORCID profile, nor will your information be shared with the manuscripts authors. Amidst all these changes we, the editorial team of Advanced Electronic Materials, have remained committed to our mission to cover the latest, most important research topics in our fields and the community has responded by flocking to the journal. Submissions have increased by 30%, which unfortunately implies that we have had to become more selective and turn away more authors than we would like. Thankfully, our transfer program to sister titles continues to grow steadily with new titles launched every year and allows us to offer our authors ever more venues to publish with us. Some of the outstanding research papers published recently may be found and freely accessed at the end of this article. Finally, I would like to congratulate the editorial team for another successful year and thank them for their unwavering efforts. And to quote Stephen Chobsky; “Things change. And friends leave. Life doesn't stop for anybody”. Thank you all for being consumate professionals and for making our journal the success that it is. Hakim Meskine Editor-in-Chief Mario Lanza and co-authors Recommended Methods to Study Resistive Switching Devices [Progress Report] Zexin Feng, Han Yan, Zhiqi Liu Electric-Field Control of Magnetic Order: From FeRh to Topological Antiferromagnetic Spintronics [Review] Raphael Pfattner, Amir M. Foudeh, Shucheng Chen, Weijun Niu, James R. Matthews, Mingqian He, Zhenan Bao Dual-Gate Organic Field-Effect Transistor for pH Sensors with Tunable Sensitivity [Full Paper] Meng Liao, Lei Ye, Ye Zhang, Taiqiang Chen, Huisheng Peng The Recent Advance in Fiber-Shaped Energy Storage Devices [Review] Tsao, J. Y., Chowdhury, S., Hollis, M. A. et al. Ultrawide-Bandgap Semiconductors: Research Opportunities and Challenges [Review] Shu Gong, Wenlong Cheng One-Dimensional Nanomaterials for Soft Electronics [Review] Fei Hui, Enric Grustan-Gutierrez, Shibing Long, Qi Liu, Anna K. Ott, Andrea C. Ferrari, Mario Lanza Graphene and Related Materials for Resistive Random Access Memories [Review] Xin Chen, Xu Han and Fun-Don Cheng PVDF-Based Ferroelectric Polymers in Modern Flexible Electronics [Review] Cedric Couly, Mohamed Alhabeb, Katherine L. Van Aken, Narendra Kurra, Luisa Gomes, Adriana M. Navarro-Suárez, Babak Anasori, Husam N. Alshareef, Yury Gogotsi Asymmetric Flexible MXene-Reduced Graphene Oxide Micro-Supercapacitor [Full Paper]

Flame-sculptured micron-porous silver wire for fiber-shaped energy storage and surface-enhanced Raman scattering

Micron-porous metal wires have attracted great attention because of their important application for fiber-shaped biosensor, energy and catalysis devices. Herein, we report a novel direct-flame approach for in-situ sculpturing micron-porous structures on the surfaces of Ag wire precursors. The heat and H2–CO–O2 mixed gas generated by the flame of ethanol ascribe to the fast creation of micron-pores on the Ag wires. This process is simple, green and cost-effective, avoiding the use of sacrificial materials or templates required by conventional techniques. The obtained micron-porous Ag wire (MPAW) is useable as a high performance self-supported microelectrode for fiber-shaped electrochemical supercapacitors. Moreover, the MPAW is applicable as a highly active and reusable microprobe for surface-enhanced Raman scattering.

A stretchable high performance all-in-one fiber supercapacitor

Flexible energy storage electronics are gaining increasing attention in recent years, but challenge still remains in obtaining fiber-shaped devices with both high specific capacitance to provide a high energy density and mechanical stretchability/flexibility to be able to integrate under extensive bending, stretching and twisting. Here, an all-in-one fiber high performance stretchable supercapacitor is constructed based on high performance bead-like NiCo2S4@carbon nanotube and Ti3C2Tx@N/O enriched carbon cloth threads electrodes. The assembled stretchable supercapacitor demonstrates a voltage output of 1.5 V and a specific areal capacitance of 559.3 mF cm−2, resulting in a high energy density of 174.78 μWh cm−2, outperforming most of previously reported stretchable fiber-shaped supercapacitors. Moreover, the high energy storage performances are well preserved under repeatedly stretching and bending. This unique design opens up a new direction in the development of stretchable fiber-shaped energy storage devices.

Recent Advances in Fiber-Shaped Supercapacitors and Lithium-Ion Batteries.

The rapid development in wearable electronics has spurred a great deal of interest in flexible energy storage devices, particularly fiber-shaped energy storage devices (FSESDs), such as fiber-shaped supercapacitors (FSSCs) and fiber-shaped batteries (FSBs). Depending on their electrode configurations, FSESDs can contain five differently structured electrodes, including parallel fiber electrodes (PFEs), twisted fiber electrodes (TFDs), wrapped fiber electrodes (WFEs), coaxial fiber devices (CFEs), and rolled electrodes (REs). Various rational methods have been devised to incorporate these fiber-shaped electrodes into multifunctional FSESDs, including fiber-shaped supercapacitors, lithium-ion batteries, lithium-sulfur batteries, lithium-air batteries, zinc-air batteries, and aluminum-air batteries. Although significant progress has been made in FSESDs, it remains a major challenge to make high-performance fiber-shaped devices at low cost. A focused and critical review of the recent advancements in fiber-shaped supercapacitors and lithium-ion batteries is provided here. The pros and cons for each of the aforementioned electrode configurations and FSESDs are discussed, along with current challenges and future opportunities for FSESDs.

Giant two-dimensional titania sheets for constructing a flexible fiber sodium-ion battery with long-term cycling stability

Following the rapid development of wearable technology, fiber-shaped energy storage systems integrating the merits of being lightweight and flexible are receiving unprecedented attention. Meanwhile, considering the increasing concerns for the scarcity of lithium (Li) resources, research on rechargeable batteries that use sodium (Na) as the shuttling ion is rapidly growing. As yet, there have been very few successful demonstrations of fiber-shaped Na-ion batteries, probably due to the lack of mechanically stable electrodes that can sustain the insertion of large-sized Na ions. Herein, by stacking giant two-dimensional sheet forms of an electrochemically active material, titania, along with reduced graphene oxide (rGO), into a belt-shape and placing one-dimensional carbon nanotubes (CNTs) sporadically between the neighboring sheets, a fiber electrode with decent Na-ion storage performance was successfully obtained. Benefiting from the conformal stacking of the electrochemically active and charge-collecting components, the fiber electrode did not require any conducting backbones, and thus exhibited outstandingly robust integrity. The incorporation of CNTs with a differing dimension disordered the stacking structure, which opened up paths for Na-ion intercalation, thus enabling exceptionally long-term reversible Na-ion intercalation/deintercalation, even under bending conditions. This work developed a new paradigm toward designing novel fiber electrodes that can host large alkaline ions for use in future flexible and portable electronic devices.

One-step Production of Continuous Supercapacitor Fibers for a Flexible Power Textile

Given that conventional bulky electrochemical energy storage devices are too rigid and heavy to be considered wearable, developing fully integrated power systems is expected to accelerate the successful commercialization of smart electronic textiles. Although great achievements have been made for fiber-shaped energy storage devices, there remain key challenges pertaining to their fabrication efficiency, scalability, and stability. Herein, a general and highly efficient method is developed to continuously fabricate supercapacitor fibers with lengths of kilometers at high production rate up to 118 m/h through a simple one-step wet spinning method. Beneficial from the designed unique two-circle-in-one-circle architecture, the resulting supercapacitor fibers demonstrated high electrochemical stability even after being bended for 1 × 105 cycles. As a demonstration, these continuous supercapacitor fibers were further woven into a flexible power scarf for large-scale applications in wearable electronics. This simple and scalable fabrication process combined with the unique structure provides a general and effective paradigm to design other fiber-shaped devices like sensors, batteries, and solar cells.

Amphiphilic core-sheath structured composite fiber for comprehensively performed supercapacitor

As an important branch of fiber-shaped energy storage devices, the fiber-shaped supercapacitor has been widely studied recently. However, it remains challenging to simultaneously achieve fast electron transport and excellent ion accessibility in one single fiber electrode of the fiber-shaped supercapacitor. Herein, a novel family of amphiphilic core-sheath structured carbon nanotube composite fibers has been developed and applied to the fiber-shaped supercapacitor to address the above challenge. The polyaniline-modified hydrophilic sheath of the composite fiber electrode effectively enhanced the electrochemical property via advancing ion accessibility, while Au-deposited hydrophobic core demonstrated improved electrical conductivity by fast electron supply. On the basis of a synergistic effect, a remarkable specific capacitance of 324 F cm−3 at 0.5 A cm−3 and greatly enhanced rate performance were achieved, i.e., a 79% retention (256 F cm−3) at 50 A cm−3. The obtained fiber-shaped supercapacitor finally displayed remarkable energy and power densities of 7.2 mW h cm−3 and 10 W cm−3, respectively. The strategy developed herein also presents a general pathway towards novel fiber electrodes for high-performance wearable devices.

NiO-bridged MnCo-hydroxides for flexible high-performance fiber-shaped energy storage device

Flexible fiber-shaped supercapacitors (FFSSs) hold promising prospect to meet the increasingly high requirements of the wearable electronics. However, today it remains a great challenge to construct advanced supercapacitor with high areal capacity and favorable rate capability to achieve superior energy density in facile route is a great challenge. Herein, we directly used the low-cost nickel wire as the fiber substrate to in-situ grow compacted NiO buffer layer capable of strongly grafting the outer MnCo-Layered double hydroxide (MnCo-LDH) with high electrochemical reversibility. Compared to MnCo-LDH directly growing on nickel fiber in the absence of NiO, the NiO@MnCo-LDH exhibited 210% enhancement in areal capacity (165.6 mC cm−2/368.1 mF cm−2 at 0.5 mA cm−2) and ultrahigh rate capability (85% retention at 20 mA cm−2), as synthesized NiO buffer not only served as “nano glue” to strongly immobilize the active materials on the metal substrate but also positively supplied extra capacitance. Thusly, the assembled hybrid/asymmetric fiber device presented a high energy density of 0.0198 mWh cm−2 at a power density of 0.38 mW cm−2 to drive a digital watch, demonstrating its promising potential application in electronic devices. This rational design sheds light on the synthesis of nickel fiber-based supercapacitor with high energy delivery.

Energy storage mechanism in aqueous fiber-shaped Li-ion capacitors based on aligned hydrogenated-Li4Ti5O12 nanowires.

It is reported that Li ions can contribute a lot to the capacitance of aqueous Li-ion capacitors (LICs), which might be due to the intercalation/de-intercalation processes of Li+ ions that also occur at the anodes. However the energy storage mechanism in the aqueous LIC system still requires further proof. In this work, a type of aqueous fiber-shaped LIC has been designed and developed using hydrogenated Li4Ti5O12 (H-LTO) anodes, active carbon (AC) cathodes, and LiCl/PVA gel electrolytes with a double-helical structure. The obtained single LTO wire electrode exhibits a high specific capacitance in volume (34.1 F cm-3) and superior cycling stabilities (∼100% over 100 000 cycles), both of which are due to the formed amorphous layers at the surface of the electrodes. Moreover, it is found via sweep voltammetry analysis that most of the energy stored in an aqueous fiber-shaped capacitor electrode is attributed to the Li ions' intercalation, whose content exceeds 85% at a low scan rate and gradually decreases with increasing scan rate; while the energy stored by the double electric layers remains almost unchanged with different scan rates. Furthermore, the well-matched wearable fiber-shaped LICs show high capacitive behaviors (18.44 μW h cm-2) and superior static/dynamic cycling stabilities. This research would provide some insight into the charge storage mechanism in electrodes in the aqueous system, and give more suggestions to develop high-energy-density fiber-shaped energy storage devices.