Advances in the miniaturization of electronic devices have allowed the rapid development of wearable technologies and envisioned seamless and user-friendly smart systems with Owing to their high safety and reversibility, aqueous microbatteries using zinc anodes and an acid electrolyte have emerged as promising candidates for wearable electronics. However, a critical limitation that prevents implementing zinc chemistry at the microscale lies in its spontaneous corrosion in an acidic electrolyte that causes a capacity loss of 40% after a ten-hour rest. Widespread anti-corrosion techniques, such as polymer coating, often retard the kinetics of zinc plating/stripping and lack spatial control at the microscale. Here, a polyimide coating that resolves this dilemma is reported. The coating prevents corrosion and hence reduces the capacity loss of a standby microbattery to 10%. The coordination of carbonyl oxygen in the polyimide with zinc ions builds up over cycling, creating a zinc blanket that minimizes the concentration gradient through the electrode/electrolyte interface and thus allows for fast kinetics and low plating/stripping overpotential. The polyimide's patternable feature energizes microbatteries in both aqueous and hydrogel electrolytes, delivering a supercapacitor-level rate performance and 400 stable cycles in the hydrogel electrolyte. Moreover, the microbattery is able to be attached to human skin and offers strong resistance to deformations, splashing, and external shock. The skin-mountable microbattery demonstrates an excellent combination of anti-corrosion, reversibility, and durability in wearables. The ORCID identification number(s) for the author(s) of this article can be found under

Hydrogels are widely used in flexible aqueous batteries due to their liquid-like ion transportation abilities and solid-like mechanical properties. Their potential applications in flexible and wearable electronics introduce a fundamental challenge: how to lower the freezing point of hydrogels to preserve these merits without sacrificing hydrogels' basic advantages in low cost and high safety. Moreover, zinc as an ideal anode in aqueous batteries suffers from low reversibility because of the formation of insulative byproducts, which is mainly caused by hydrogen evolution via extensive hydration of zinc ions. This, in principle, requires the suppression of hydration, which induces an undesirable increase in the freezing point of hydrogels. Here, it is demonstrated that cooperatively hydrated cations, zinc and lithium ions in hydrogels, are very effective in addressing the above challenges. This simple but unique hydrogel not only enables a 98% capacity retention upon cooling down to −20 °C from room temperature but also allows a near 100% capacity retention with >99.5% Coulombic efficiency over 500 cycles at −20 °C. In addition, the strengthened mechanical properties of the hydrogel under subzero temperatures result in excellent durability under various harsh deformations after the freezing process.

No abstract

Advances in microelectronics have led to the development of on-chip intelligent microsystems that can digitalize the physical world, offering functions of sensing, data communication, and intelligent response to stimuli. Either mismatched form factors or limited energy density of available batteries compromises their integration. We report a microimprint fabrication for on-chip Zn−air microbatteries, which bypasses the complication of the catalyst incorporation on the chip at a target position. The on-chip integration of a bifunctional catalyst covalent organic framework with cobalt catalytic unitsenables the onchip Zn−air microbattery to outperform the Zn−air primary cell, showing 3 times more volumetric energy density. It is wirelessly chargeable, and its lifetime capacity is around twice longer than that for commercially available on-chip lithium ion microbatteries. The on-chip Zn−air microbattery can drive various electronic systems. Our approach bridges a long-standing gulf between advanced materials synthesis and their on-chip integration and paves the way toward high-performance on-chip Zn−air batteries.

No abstract

No abstract

Dissolved oxygen is a critical factor for heterotrophic cell growth and metabolite production. The aim of this study was to investigate the effects of an oxygen-involved protein on cell growth and fatty acid and astaxanthin production in the biologically important thraustochytrid Aurantiochytrium sp. The hemoglobin of the Vitreoscilla stercoraria (VHb) gene was fused upstream with a zeocin resistance gene (ble) and driven by the Aurantiochytrium tubulin promoter. The expression construct was introduced into two strains of Aurantiochytrium sp. by electroporation. Transgenic Aurantiochytrium sp. strains MP4 and SK4 expressing the heterologous VHb achieved significantly higher maximum biomass than their corresponding controls in microaerobic conditions. Furthermore, the transformants of Aurantiochytrium sp. SK4 produced 44% higher total fatty acid and 9-fold higher astaxanthin contents than the wild type control in aerobic conditions. The present study highlights the biotechnological application of VHb in high-cell density fermentation for enhanced biomass production as well as high-value metabolites.

High energy density, recyclability, and manufacturing flexibility are valuable assets for batteries to drive the Internet of Things in a distributed, adaptive, and sustainable way. Aqueous zinc batteries are environmentally benign and offer more flexibility in manufacturing processes but are plagued by limited energy densities because of an operating voltage below 2 V. Here, we demonstrate a cathodeless battery with decoupled reactions successfully raising the voltage up to 2 V. The decoupled hydrogel electrolyte design inhibits cation crossover without the use of an ion-selective membrane and suppresses oxygen evolution upon bonding water to hydrogen sulfate anions through hydrogen bonding, allowing for high energy output and a long lifespan. The elimination of electrode composite slurries transforms everyday objects into batteries. Thirty minutes of wireless charging drives a multifunction electronic device for more than a day. Hydrogel electrolytes can be easily regenerated by resoaking, inspiring a new generation of sustainable energy storage devices.