Fabrications of High‐Performance Planar Zinc‐Ion Microbatteries by Engraved Soft Templates

Abstract

Miniaturized energy storage devices (MESDs) provide future solutions for powering dispersive electronics and small devices. Among them, aqueous zinc ion microbatteries (ZIMBs) are a type of promising MESDs because of their high‐capacity Zn anode, safe and green aqueous electrolytes, and good battery performances. Herein, for the first time, a simple and powerful strategy to fabricate flexible ZIMBs based on tailored soft templates is reported, which are patterned by engraving and enables to design the ZIMBs featured with arbitrary shapes and on various substrates. The assembled ZIMBs employing α‐MnS as the cathode materials and guar gum gel as the quasi‐solid‐state electrolyte exhibited very high areal specific capacity of up to 178 μAh cm−2, a notable areal energy density of 322 μWh cm−2 and power density of 710 μW cm−2. Footprint areas of the manufactured ZIMBs as small as 40 mm2 can be achieved. The proposed method based on the engraved soft templates provides a practical route for ZIMB and other MESD designs, which is critical for portable and wearable electronics development.

Electrochemical reaction behavior of MnS in aqueous zinc ion battery

“…Jiang et al reported flexible zinc ion microbatteries with the α-MnS cathode. 7 The as-prepared microbatteries delivered a high areal capacity of 178 μA h cm −2 and an energy density of up to 322 μW h cm −2 at the power density of 120 μW cm −2 . These pioneering research efforts show feasibility and suitability of MnS as zinc ion batteries' cathode material.…”

“…3,4 The rechargeable aqueous metal ion batteries, which are assembled with aqueous solution electrolyte and earth abundant metal anode (e.g., Zn, Mg, and Al), are being revived due to their advantages of simple and convenient assembly, admirable security, and decent ionic conductivity. [5][6][7] Among them, the rechargeable zinc ion battery has aroused considerable attention due to its admirable safety, cost-effectiveness, moderate redox potential (−0.76 V vs. SHE), and decent theoretical capacity (∼820 mA h g −1 ) of the Zn anode. 6,8,9 However, the zinc ion battery is still in its infancy, and one of the core tasks aim to prompt the development of the zinc ion battery is to screen out competent cathode materials that can sustainably serve for repeated Zn 2+ intercalation/deintercalation.…”

“…4,14,[16][17][18][28][29][30][31] Most recently, MnS x , which is known as another important manganese-based compounds, has also been introduced in zinc ion batteries. 7,8,32,33 For instance, Chen et al activated Zn-inactive MnS by in situ electrochemically converting it into Mn oxides in zinc ion battery. 8 The Mn oxides derived from MnS show improved Zn ion diffusion kinetics and higher electrochemically active surface areas than α-MnO 2 .…”

A Flexible Aqueous Zinc–Iodine Microbattery with Unprecedented Energy Density

“…[27] Besides, this microdevice also shows a small series resistance (Figure S14, Supporting Information). At the low current density of 2 mA cm −2 , a maximum areal specific capacity of 1932.3 μAh cm −2 is achieved (Figure 3f,g; Table S1, Supporting Information), far exceeding those of all reported aqueous MBs, [15][16][17][19][20][21][22][23][52][53][54][55][56][57] highperformance organic MBs (lithium-ion MBs, [12,24,58,59] sodiumion MBs, [60] and dual-ion MBs [61] ), state-of-the-art zinc-ion MSCs, [62,63] and lithium-ion MSCs [64] (Figure 3i). Even at higher current densities of 8 and 10 mA cm −2 , it still exhibits excellent areal specific capacity of 622.43 and 407 μAh cm −2 with high Coulombic efficiency of 97.4% and 98.1%, respectively (Figure 3f,g).…”

Printed Zinc Paper Batteries

“…The other type of paper zinc‐ion batteries employs the paper only as the substrate, in which the batteries are in‐plane printed on one side and present interdigitated configuration. [ 28 , 29 ] Printing electrode inks on both sides is challenging because it may cause short of the battery due to the rough and permeable surface of paper. Accordingly, the printed micro‐batteries on paper deliver limited areal capacity and volumetric energy density (up to ≈10 mWh cm –3 ).…”