3D Printed Stretchable Liquid Gallium Battery

Abstract

Despite the rapid progress on soft and stretchable batteries, current fabrication techniques involve manual disposition and stencil/screen printing. Here, for the first time, a 3D-printed Ag-Ga battery is introduced through subsequent printing of four sinter-free composites: a stretchable Liquid Metal (LM) EGaIn-Ag-Styrene-isoprene block copolymers (SIS), and Carbon-SIS current collectors; Ag 2 O-SIS cathode; and a novel Ga-C-SIS anode. Being sinter-free results in faster printing, and compatibility with heat-sensitive substrates. Although the Ga-C-SIS is solid-like and nonsmearing after printing, it creates a liquid interface after contacting with the electrolyte. This results in a self-feeding and self-aggregation mechanism that brings more gallium to the surface and delays the formation of the dead surface. The recordbreaking areal capacity of ≈19.4 mAh cm −2 , along with excellent stretchability (>130% Max. strain), makes the Ag-Ga battery an excellent alternative to Ag-Zn batteries. Surprisingly, digital printing results in 3x higher areal capacity compared to stencil printing, due to greater gallium exposure at the surface. The desired voltage and current output can be customized by printing several battery cells and interconnect them in series/parallel. Also, printing of sensors, electrodes, batteries, and interconnects on a biomonitoring e-textile for simultaneous monitoring of electrocardiography, body temperature, and respiration is demonstrated.

Multi‐Electrode Printed Bioelectronic Patches for Long‐Term Electrophysiological Monitoring

“…Further research will focus on integrating adhesive characteristics on the biphasic composites to improve their interfacial properties in subjects with high body hair density and promote an even better conformal contact with the skin's microtexture. Furthermore, to completely avoid the possibility of the thick rigid battery being dethatched from the body due to applied forces from more intense physical exercise, the possibility of integrating a thin printed stretchable battery [4,72] should be investigated. In addition, current and future attempts on direct integration of microchips into stretchable circuits have the potential to contribute toward the next generation of hybrid stretchable circuits that better conform to human skin.…”

Smart Eutectic Gallium–Indium: From Properties to Applications

“…These LM-based heat management devices, [24,25,93,292] motors, [43,[293][294][295][296] generators, [28,297,298] batteries, [29,30,[299][300][301] and other energy devices have opened up a new direction for the development of next generation of high-performance, multifunctional, and flexible devices. Thermal Management: The high thermal conductivity of liquid metals can be used for heat management.…”

“…With the advent of the low‐carbon era, a new generation of LM‐based energy harvesting devices has gradually been developing. These LM‐based heat management devices, [ 24,25,93,292 ] motors, [ 43,293–296 ] generators, [ 28,297,298 ] batteries, [ 29,30,299–301 ] and other energy devices have opened up a new direction for the development of next generation of high‐performance, multi‐functional, and flexible devices.…”

Elastic Fibers/Fabrics for Wearables and Bioelectronics

“…SC [ 188,189] Battery [ 190,191] TENG [192,193] PENG [194,195] Finishing Sensor [ 196,197] SC [ 198,199] Battery [ 200,201] TENG [202,203] Thermal management [ 204,205] which has gradually sparked a revolution in energy management for driving micro-/nanoelectronics. [151,155,184,[218][219][220] Based on different working mechanism, piezoelectric nanogenerator (PENG), triboelectric nanogenerator (TENG), and thermoelectric nanogenerator (TEG) exhibit respective advantages in device cost, power output, and operation environment.…”