Facile Development Strategy of a Single Carbon-Fiber-Based All-Solid-State Flexible Lithium-Ion Battery for Wearable Electronics

Abstract

Microsized and shape-versatile flexible and wearable lithium-ion batteries (LIBs) are promising and smart energy storage devices for next-generation electronics. In the present work, we design and fabricate the first prototype of microsized fibrous LIBs (thickness ≈ 22 μm) based on multilayered coaxial structure of solid-state battery components over flexible and electrically conductive carbon fibers (CFs). The micro coaxial batteries over the CF surface were fabricated via electrophoretic deposition and dip-coating methods. The microfiber battery showed a stable potential window of 2.5 V with an areal discharge capacity of ∼4.2 μA h cm–2 at 13 μA cm–2 of the current density. The as-assembled battery fiber delivered a comparable energy density (∼0.006 W h cm–3) with solid-state lithium thin-film batteries at higher power densities (∼0.0312 W cm–3). The fibrous batteries were also connected in parallel and in series to deliver large current and high voltage, respectively. The fibrous battery also retains up to 85% discharge capacity even after 100 charge–discharge cycles. Furthermore, these battery fibers performed well under both static and bending conditions, which shows the robustness of the battery fiber. Therefore, this type of fibrous microbattery can be used in advanced flexible and wearable microelectronics, bioelectronics, robotics, and textile applications.

A Route Toward Smart System Integration: From Fiber Design to Device Construction

“…e) Schematic diagram of battery components on a single battery fiber. Reproduced with permission . Copyright 2019, American Chemical Society.…”

“…For LIBs, there also exist coaxial fiber‐shaped LIBs . The first attempt was made based on a core of hollow‐spiral Cu wires, which were then coated by Ni–Sn layer, separator, LiCoO 2 paste and finally wound by Al wires (Figure d).…”

“…Because of the thick hollow‐spiral Cu wires, the flexibility of this fiber‐shaped LIB was not good enough. Recently, carbon fiber was used as the core fiber, which was coated by lithium iron phosphate via electrophoretic deposition as the cathode, PEO‐based solid electrolyte, lithium titanate as the anode and finally conductive outer layer (Figure e) . Moreover, coaxial fiber‐shaped LIBs can be constructed by winding anode and cathode fibers on a fiber core that works only as a structural supporter.…”

Rational Modulation of Carbon Fibers for High‐Performance Zinc–Iodine Batteries

“…Note that couples of tunable factors of carbon fiber are also responsible for the adsorption property of iodine and subsequent electrochemical performance of ZIBs assembled with carbon fibers, including the pore size and specific surface area, surface chemical properties caused by the heteroatom doping, [ 31,32 ] and surface functionalization with additional materials. [ 33–35 ] With the significant advances on Zn–I 2 batteries, recent research works on the modulation of carbon nanofiber via the physical and chemical strategies to enhance the battery performance are summarized, with specific focus on strengthening the interaction between iodine and carbon fibers. The basic principles would provide novel insight into the rational design of advanced iodine‐based cathodes for high‐performance ZIBs.…”

Bio-cleaning improves the mechanical properties of lignin-based carbon fibers

“…Carbon bers (CF) and CF reinforced composite materials are heavily used in a broad range of elds that are strategically critical, such as composite materials and energy. Some of the important applications that utilize CF are aviation, 1 aerospace, 2 sensors, batteries, 3,4 and supercapacitors. 5,6 The advantages of using CF in various applications include its light weight, large surface area to volume ratio and strength to weight ratio, high exibility, corrosion resistance, etc.…”