Pt-based catalysts are the most active materials for the oxygen reduction reaction in Zn-air batteries; however, most Pt-based catalysts are unfavorable for the adsorption of OOH* intermediates, which hampers battery efficiency. To address this, a strategy for precisely constructing Pt-Co alloy atomic configurations enables the immobilization and controlled release of OOH* intermediates during the four-electron O₂ reduction reaction. Using the synthetic Pt₁Co alloy nanoparticles encapsulated in N-doped carbon nanotubes (Pt₁Co-NP@NCNTs) as an example, characterization via synchrotron-radiation X-ray absorption fine structure and high-angle annular dark-field scanning transmission electron microscopy confirms that Pt single atoms are uniformly dispersed on Co nanoparticles. In situ attenuated total reflectance-surface enhanced infrared absorption spectroscopy further verifies that these Pt₁Co alloy nanoparticles facilitate the immobilization of OOH* intermediates and the release of OH* intermediates, ensuring efficient H₂O production through the four-electron pathway. As a result, the Pt₁Co-NP@NCNTs exhibit outstanding oxygen reduction reaction activity with a high half-wave potential of 0.90 V vs. RHE, and when integrated into Zn-air batteries, they deliver a high power density of 141 mW cm^-2 and an ultralong lifespan exceeding 300 hours at 10 mA cm^-2, outperforming most Pt-based electrocatalysts in rechargeable Zn-air batteries.

Aqueous rechargeable zinc ion batteries have received widespread attention due to their high energy density and low cost. However, zinc metal anodes face fatal dendrite growth and detrimental side reactions, which affect the cycle stability and practical application of zinc ion batteries. Here, an in-situ formed hierarchical solid-electrolyte interphase composed of InF₃, In, and ZnF₂ layers with outside-in orientation on the Zn anode (denoted as Zn@InF₃) is developed by a sample InF₃ coating. The inner ultrathin ZnF₂ interface between Zn anode and InF₃ layer formed by the spontaneous galvanic replacement reaction between InF₃ and Zn, is conductive to achieving uniform Zn deposition and inhibits the growth of Zinc dendrites due to the high electrical resistivity and Zn²⁺ conductivity. Meanwhile, the middle uniformly generated metallic In and outside InF₃ layers functioning as corrosion inhibitor suppressing the side reaction due to the waterproof surfaces, good chemical inactivity, and high hydrogen evolution overpotential. Besides, the as-prepared zinc anode enables dendrite-free Zn plating/stripping for more than 6,000 h at nearly 100% coulombic efficiency (CE). Furthermore, coupled with the MnO₂ cathode, the full battery exhibits the long cycle of up to 1,000 cycles with a low negative-to-positive electrode capacity (N/P) ratio of 2.8.

Aqueous rechargeable sodium ion batteries (ARSIBs), with intrinsic safety, low cost, and greenness, are attracting more and more attentions for large scale energy storage application. However, the low energy density hampers their practical application. Here, a battery architecture designed by bipolar electrode with graphite/amorphous carbon film as current collector shows high energy density and excellent rate-capability. The bipolar electrode architecture is designed to not only improve energy density of practical battery by minimizing inactive ingredient, such as tabs and cases, but also guarantee high rate-capability through a short electron transport distance in the through-plane direction instead of in-plane direction for traditional cell architecture. As a proof of concept, a prototype pouch cell of 8 V based on six Na₂MnFe(CN)₆||NaTi₂(PO₄)₃ bipolar electrodes stacking using a “water-in-polymer” gel electrolyte is demonstrated to cycle up to 4,000 times, with a high energy density of 86 Wh·kg⁻¹ based on total mass of both cathode and anode. This result opens a new avenue to develop advance high-energy ARSIBs for grid-scale energy storage applications.