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.

Enhancing ionic conductivity of quasi‐solid‐state electrolytes (QSSEs) is one of the top priorities, while conventional metal–organic frameworks (MOFs) severely impede ion migration due to their abundant grain boundaries. Herein, ZIF‐4 glass, a subset of MOFs, is reported as QSSEs (LGZ) for lithium‐metal batteries. With lean Li content (0.12 wt%) and solvent amount (19.4 wt%), LGZ can achieve a remarkable ion conductivity of 1.61 × 10⁻⁴ S cm⁻¹ at 30 °C, higher than those of crystalline ZIF‐4‐based QSSEs (LCZ, 8.21 × 10⁻⁵ S cm⁻¹) and the reported QSSEs containing high Li contents (0.32–5.4 wt%) and huge plasticizer (30–70 wt%). Even at −56.6 °C, LGZ can still deliver a conductivity of 5.96 × 10⁻⁶ S cm⁻¹ (vs 4.51 × 10⁻⁷ S cm⁻¹ for LCZ). Owing to the grain boundary‐free and isotropic properties of glassy ZIF‐4, the facilitated ion conduction enables a homogeneous ion flux, suppressing Li dendrites. When paired with LiFePO₄ cathode, LGZ cell demonstrates a prominent cycling capacity of 101 mAh g⁻¹ for 500 cycles at 1 C with the near‐utility retention, outperforming LCZ (30.7 mAh g⁻¹) and the explored MOF‐/covalent–organic frameworks (COF)‐based QSSEs. Hence, MOF glasses will be a potential platform for practical quasi‐solid‐state batteries in the future.

The applications of thermoelectric (TE) technology around room temperature are monopolized by bismuth telluride (Bi₂Te₃). However, due to the toxicity and scarcity of tellurium (Te), it is vital to develop a next-generation technology to mitigate the potential bottleneck in raw material supply for a sustainable future. Hereby, we develop a Te-free n-type compound Mg₃Sb_0.6Bi_1.4 for near-room-temperature applications. A higher sintering temperature of up to 1073 K is found to be beneficial for reducing the electrical resistivity, but only if Mg is heavily overcompensated in the initial stoichiometry. The optimizations of processing and doping yield a high average zT of 1.1 in between 300 K and 573 K. Together with the p-type MgAgSb, we demonstrate module-level conversion efficiencies of 3% and 8.5% under temperature differences of 75 K and 260 K, respectively, and concomitantly a maximum cooling of 72 K when the module is used as a cooler. Besides, the module displays exceptional thermal robustness with a < 10% loss of the output power after thermal cycling for ∼32 000 times between 323 K and 500 K. These proof-of-principle demonstrations will pave the way for robust, high-performance, and sustainable solid-state power generation and cooling to substitute highly scarce and toxic Bi₂Te₃.