3D‐Printed All‐Fiber Li‐Ion Battery toward Wearable Energy Storage

Abstract

Conventional bulky and rigid power systems are incapable of meeting flexibility and breathability requirements for wearable applications. Despite the tremendous efforts dedicated to developing various 1D energy storage devices with sufficient flexibility, challenges remain pertaining to fabrication scalability, cost, and efficiency. Here, a scalable, low-cost, and high-efficiency 3D printing technology is applied to fabricate a flexible all-fiber lithium-ion battery (LIB). Highly viscous polymer inks containing carbon nanotubes and either lithium iron phosphate (LFP) or lithium titanium oxide (LTO) are used to print LFP fiber cathodes and LTO fiber anodes, respectively. Both fiber electrodes demonstrate good flexibility and high electrochemical performance in half-cell configurations. All-fiber LIB can be successfully assembled by twisting the as-printed LFP and LTO fibers together with gel polymer as the quasi-solid electrolyte. The all-fiber device exhibits a high specific capacity of ≈110 mAh g −1 at a current density of 50 mA g −1 and maintains a good flexibility of the fiber electrodes, which can be potentially integrated into textile fabrics for future wearable electronic applications.

3D‐Printed Structure Boosts the Kinetics and Intrinsic Capacitance of Pseudocapacitive Graphene Aerogels

“…Direct ink writing (DIW) is one of the most commonly used 3D‐printing techniques. It offers great flexibility in the material (ink) selection and has been recently applied to prepare electrodes for electrochemical energy storage devices, including lithium‐ion batteries, sodium‐ion batteries, lithium–sulfur batteries, lithium metal batteries, and supercapacitors . In comparison to bulk electrodes, these 3D‐printed electrodes have shown improved electrolyte infiltration and ion diffusion …”

Recent Progress in Flexible Fibrous Batteries

“…It has attracted greatly attention due to its good scalability, low cost and ability to complete complex work. Wang et al reported on a scalable, low‐cost and high‐efficiency three‐dimension printing technology to fabricate a flexible fibrous LIB using lithium iron phosphate as cathodes and lithium titanate as anodes . The electrode materials of LiFePO 4 and Li 4 Ti 5 O 12 were added together with the carbon nanotube conductive additive and added to the polyvinylidene difluoride solution to form cathode and anode inks for printing LiFePO 4 (cathode) and Li 4 Ti 5 O 12 (anode) fibers.…”

The Recent Advance in Fiber‐Shaped Energy Storage Devices

“…Generally, in Li-S battery system, the sulfur-based cathode can effectively lower the cost of devices, while its lithiated intermediate, soluble polysulfides are prone to make capacity degradation and decreased lifespan. [54] Copyright 2017, Wiley-VCH. Flexible, highly conducting and self-standing sulfur cathode were successfully prepared with activated carbon fiber cloth and template-synthesized CNT membranes, [56,57] blazing the direction for the realization of fiber-shaped Li-S battery.…”

“…Polyimide/CNT hybrid fiber; LiMn 2 O 4 /CNT hybrid fiber [49] In parallel 86 mAh g −1 at 600 C Can be woven into flexible battery textile Li 4 Ti 5 O 12 /CNT/PVDF and LiFP 6 /CNT/PVDF inks [54] Twisted 110 mAh g −1 at 50 mA g −1 Can be woven into fabric Lithium-sulfur battery CNT fiber incorporated with CMK-3/S; lithium wire [58] Cable type First discharge capacity of 1051 mAh g −1 at 0.1 C…”