Discharge Products Research Articles

Tracing Sulfate Sources of Surface Water and Groundwater in Liuyang River Basin Based on Hydrochemistry and Environmental Isotopes

Sulfate as a potential pollution source in the water environment of the basin, identifying sulfate sources and migration mechanisms is essential for protecting the water environment and ensuring sustainable water management. Liuyang River is a primary tributary of the Xiangjiang River. It has experienced progressively intensifying anthropogenic influences in recent decades, manifested by sustained sulfate concentration increases. However, the sulfate sources and their contributions were not clear. This study used hydrochemistry and multi-isotopes methods combined with Simmr model to study the hydrochemical characteristics, sulfate sources, and migration–transformation processes of surface water and groundwater. The results showed that the hydrochemical types of surface water were HCO3-Ca and HCO3·SO4-Ca·Mg, and groundwater were HCO3-Ca, HCO3-Ca·Mg, and HCO3·SO4-Ca. Ions in the water primarily originated from carbonate and silicate rocks dissolution and sulfide oxidation, augmented by mining operations, sewage discharge, and chemical production. The analyses of hydrochemistry, isotopes, and Simmr model revealed that surface water sulfate originated from soil sulfate (35.70%), sulfide oxidation (26.56%), sewage (16.58%), and atmospheric precipitation (12.45%). Groundwater sulfate was derived predominantly from sewage (34.96%), followed by soil sulfate (28.09%), atmospheric precipitation (17.35%), and sulfide oxidation (12.25%). Sulfate migration and transformation were controlled by the natural environment and anthropogenic impacts. When unaffected by human activities, sulfate mainly originated from soil and atmospheric precipitation, relating to topography, geological conditions, agricultural activities, and precipitation intensity. However, in regions with intense human activities, contributions from sewage and sulfide oxidation significantly increased due to the influences of mining and industrial activities.

Unlocking the Power of Lewis Basicity in Oxide Lattice Oxygens: A Regulating Force for Enhanced Oxygen Evolution Kinetics in Li‐O2 Batteries

Abstract Lithium‐oxygen batteries (LOBs) require fast oxygen conversion kinetics to achieve good cycling performance and high energy efficiency. In the text of catalysts for LOBs, the Lewis basicity of lattice oxygens (OL) in common transition metal oxides is often underestimated due to the weak electron donor characteristic of OL. In this work, a new spinel‐type high entropy oxide with Lewis basicity (LB‐HEO) was synthesized through a Joule‐heating method. OL was activated by regulating the tetrahedral site‐OL‐octahedral site (MTd‐OL‐MOh) units in the spinel‐type HEO, enhancing the LB. Used as a cathode catalyst for LOBs, LB‐HEO could attract Li+ and increase the disorder in discharge product, lithium peroxide (Li2O2), promoting the delithiation process and the interfacial charge transfer at the LB‐HEO|Li2O2 interface. The activation energy of interfacial charge transfer was significantly reduced from 63.5 to 22.4 kJ mol−1. As a result, a low charging overpotential of 0.97 V and a long cycling lifespan of 135 cycles at 100 mA g−1 were achieved with a capacity limitation of 1000 mAh g−1. The strategy based on the regulation of Li+ behavior through its interaction with Lewis bases provides a promising prospect for the design of non‐noble metal catalysts for high‐performance LOBs.

Modified QuEChERS extraction coupled with LC-MS/MS for the determination of per- and polyfluoroalkyl substances in sediments.

Modified QuEChERS extraction coupled with LC-MS/MS for the determination of per- and polyfluoroalkyl substances in sediments.

Unlocking the Power of Lewis Basicity in Oxide Lattice Oxygens: A Regulating Force for Enhanced Oxygen Evolution Kinetics in Li-O2 Batteries.

Lithium-oxygen batteries (LOBs) require fast oxygen conversion kinetics to achieve good cycling performance and high energy efficiency. In the text of catalysts for LOBs, Lewis basicity of lattice oxygens (OL) in common transition metal oxides is often underestimated due to the weak electron donor characteristic of OL. In this work, a new spinel-type high entropy oxide with Lewis basicity (LB-HEO) was synthesized through a Joule-heating method. OL was activated by regulating the tetrahedral site-OL-octahedral site (MTd-OL-MOh) units in the spinel-type HEO, enhancing the Lewis basicity. Used as cathode catalyst for LOBs, LB-HEO could attract Li+ and increase the disorder in discharge product, lithium peroxide (Li2O2), promoting the delithiation process and the interfacial charge transfer at the LB-HEO|Li2O2 interface. The activation energy of interfacial charge transfer was significantly reduced from 63.5 kJ mol-1 to 22.4 kJ mol-1. As a result, low charging overpotential of 0.97 V and long cycling lifespan of 135 cycles at 100 mA g-1 were achieved with capacity limitation of 1000 mAh g-1. The strategy based on the regulation of Li+ behavior through its interaction with Lewis bases provides a promising prospective for the design of non-noble metal catalysts for high-performance LOBs.

Defect-Engineered NbSx as an Efficient Cathode Host for High-Performance Li-Organosulfur Batteries.

Organosulfur molecules are considered highly promising cathode materials for lithium batteries due to their high theoretical specific capacities. However, their practical application is hindered due to the issues of the dissolution and shuttling of the discharge products, as well as the electron/ion insulation. In this study, niobium sulfide with abundant sulfur vacancies encapsulated by nitrogen-doped coral-shaped carbon (NbSx@N-CC) is synthesized using an arc discharge method and interwoven with carbon nanotubes to form an ideal host material for diphenyl tetrasulfide (PTS) as a cathode in rechargeable lithium batteries. The NbSx@N-CC catalyst can accelerate the cathodic reaction kinetics, adsorb lithium polysulfides (LiPSs) to mitigate the shuttle effect, thus significantly improving the cycling performance. At the 0.5 C rate, the battery exhibits an initial discharge capacity of 520.7 mAh g-1, with a diminutive cycle capacity decay rate of 0.067% per cycle over 500 cycles. Even under the condition of high PTS loading (6.0 mg cm-2) and low electrolyte (5 μL mg-1), the Li-PTS battery can still maintain a capacity retention rate of 97% after stably cycling 150 times at a 0.2 C rate. This work demonstrates that defect engineering is one of the effective approaches to address the challenges of lithium-organosulfur batteries.

Projection of Climate Impact on Discharge and Energy Production of Cascade Hydroelectric Power Plant in North Sulawesi

Background: Climate change is a major challenge for the sustainability of hydropower plants (PLTA) in tropical areas such as North Sulawesi, which are highly dependent on water availability from seasonal rainfall.Aims & Methods: This study aims to project the water discharge and electricity production of the Tonsealama, Tanggari I, and Tanggari II hydropower plants based on the SSP2-4.5 and SSP5-8.5 climate change scenarios. Historical climate data (2014–2024) from BMKG and hydropower plant operation data (2019–2024) are used to train the prediction model using the Random Forest algorithm, with bias correction performed on the CMIP6 GCM output through a hybrid approach combining Random Forest and Delta Change.Result: The results show a consistent decrease in discharge and energy at the three hydropower plants, especially in May, which has been the peak of the rainy season. The average annual discharge decrease reached 9%, while the decrease in electricity was recorded at 5,528.77 MWh (SSP2-4.5) and 3,053.42 MWh (SSP5-8.5) for the Tonsealama hydropower plant; 8,085.37 MWh and 12,625.98 MWh for PLTA Tanggari I; and the highest decline was experienced by PLTA Tanggari II of 18,160.42 MWh and 9,255.40 MWh. Although higher warming occurs in the SSP5-8.5 scenario, occasional extreme rainfall events partially offset the decline in energy production. These findings emphasize the importance of adaptation strategies through more flexible reservoir management, turbine operations, and integrated water resource planning to increase system resilience to future climate uncertainty.

Revealing Redox-Mediated CO2 Reduction Reaction Mechanisms in Aprotic Li-CO2 Batteries.

Redox-mediated electrocatalysis represents an innovative strategy to unlock the energy capabilities of aprotic Li-CO2 batteries by enabling solution-mediated CO2 reduction reaction (CO2RR). However, the underlying reaction pathways remain incompletely understood due to the lack of direct molecular evidence. Herein, multimodal in situ spectroscopic techniques are integrated with theoretical calculations to interrogate a model 9,10-phenanthrenequinone (PQ)-mediated CO2RR. Direct spectroscopic evidence reveals a current-density-dependent CO2RR pathway: the reduced PQ reacts with CO2 to form metastable Li2(PQ-CO2) adduct via ECE and EEC pathways at low and high current densities, respectively. Subsequently, the metastable Li2(PQ-CO2) adduct dissociates to form the LiCO2 intermediate and regenerate LinPQ (n = 0 and 1 at low and high current densities, respectively). Two LiCO2 intermediates dimerize to produce the final discharge products of Li2CO3 and CO in bulk solution. Therefore, the operation of Li-CO2 batteries at low-current densities reduces the activation barrier of CO2RR and regenerates PQ for sustained redox cycling, enabling significantly minimized overpotential and enhanced discharge capacity. Additionally, the suppression effects of weakly acidic cations (e.g., K+, TBA+) are elucidated for the redox-mediated CO2RR. This work highlights the pivotal chemical dissociation step in PQ-mediated CO₂RR and provides a mechanistic framework for designing better metal-CO2 batteries.

Dual‐Site Ni Nanoparticles‐Ru Clusters Anchored on Hierarchical Carbon with Decoupled Gas and Ion Diffusion Channels Enabling Low‐Overpotential, Highly Stable Li‐CO2 Batteries

Abstract Li‐CO₂ batteries present an innovative electrochemical approach, integrating CO₂ capture and energy storage. Nevertheless, slow CO₂ reduction and evolution reaction kinetics lead to substantial overpotentials and limited cycling lifespans. This study introduces a hierarchical gas electrode derived from wood, functionalized with nickel nanoparticles and ruthenium clusters. The three dimensional (3D) hierarchical porous structure serves dual purposes: 1) It provides separate channels for gas and ion diffusion, enhancing transport kinetics during Li‐CO₂ redox reactions. 2) It offers ample space for discharge product deposition, mitigating surface passivation. Furthermore, the dual‐site Ni–Ru active centers enhance the co‐oxidation reversibility of Li₂CO₃‐C aggregates through electronic structure optimization. This suppresses electrolyte decomposition and side reactions, especially at high current rates. These advantageous structural features enable Li‐CO₂ batteries with optimized cathodes to achieve: 1) A discharge platform below 3.16 V, 2) An ultralow discharge–charge overpotential gap of 0.619 V, 3) A full discharge capacity of 34.681 mAh cm⁻2, and 4) A long cycle life exceeding 1100 cycles (2200 h). This study presents an effective design strategy that combines electrode architecture and metal catalytic centers for gas cathodes. The findings advance the development of aprotic Li‐CO₂ batteries as a viable electrochemical energy storage solution.

Probing the Chemical Action of M-N4 Motif in Metal Phthalocyanine-Based Redox Mediators in Li-O2 Batteries.

Despite the exceptionally high theoretical specific energy of Li-O2 rechargeable batteries, their practical realization remains elusive, primarily due to the sluggish oxygen reduction/evolution kinetics and the underlying nontrivial mechanisms. Here, we systematically investigate by operando spectroscopy and DFT calculations the anchoring characteristics of various discharge (viz. metal-superoxide, metal-peroxide) and side (viz. Li2CO3, LiOH) products on the M-N4 motif of first-row transition metal phthalocyanines redox mediators (RMs) and their impact on Li-O2 battery performance. The unsaturated d-orbital and discharge products oriented between the two M-N bonds lead to stability of the Mn, Fe, and Co-based RM, low charge polarization, and superior battery performance. On the contrary, strong anchoring with the phthalocyanine ring leads to a loss of RM activity. While discharge and parasitic products coordinate more strongly with the metal center for unsaturated d-orbital RMs, for filled d-orbitals, the products coordinate with the porphyrin ring. The findings on the orientation of discharge/side products on the M-N4 motif catalyst clearly account for the polarization during the charging process. This fundamental study will aid in comprehensive molecular designs for liquid-based RM for next-generation battery systems for stationary applications.

A Rechargeable Neutral Hybrid Zn‐Air/MnO2 Battery with High Energy Efficiency

Abstract Neutral rechargeable Zn‐air batteries (ZABs) offer high energy density, safety, and cost‐effectiveness. However, energy efficiency is limited by sluggish oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) kinetics, along with the formation of low‐conductivity discharge products. Here, a high‐efficiency neutral hybrid Zn‐air/MnO2 battery (ZAMB) is introduced, where MnO2 is in situ electrodeposited on the air cathode in a ZnSO4‐MnSO4 electrolyte. The electrodeposited MnO2 acts as the active material for the Zn‐MnO2 battery and as a dynamically formed catalyst for the ORR/OER processes. In situ pH and X‐ray diffraction (XRD) analyses verify its effect in promoting the reversible formation and decomposition of low‐conductivity discharge products. The hybrid ZAMB achieves an energy efficiency of 68%, a significant increase from 38% in conventional ZABs, and exhibits better cycling stability, operating reliably over 100 h at a current density of 1 mA cm−2 and up to 300 h at 0.1 mA cm−2. A rechargeable pouch‐type ZAMB delivering a fixed capacity of 1 Ah demonstrates the practical potential of this hybrid design. This work integrates multiple electrochemical reactions in a single hybrid battery, improving energy efficiency, longevity, and the performance of metal‐air batteries with low‐conductivity discharge products.

Synergistic Zirconium‐Based Metal‐Organic Framework/Reduced Graphene Oxide Nanocomposite as a High‐Efficiency Cathode Catalyst for Rechargeable Lithium‐Oxygen Batteries

Lithium‐oxygen batteries (LOBs) are widely regarded as next‐generation energy storage technologies, owing to their exceptional theoretical energy density (~3500 Wh kg‐1). However, sluggish oxygen redox kinetics and rapid capacity degradation caused by insulating discharge products remain critical challenges. In this study, a hierarchical nanocomposite comprising zirconium‐based metal–organic frameworks (MOF) grown in situ on a three‐dimensional conductive reduced graphene oxide network is strategically fabricated via a solvothermal method. The optimised structure provides abundant active interfaces and efficient electron transport pathways, mitigating electrode surface inactivation and reaction hysteresis. Electrochemical analyses indicate that the composite cathode exhibits a remarkable specific capacity of 16680 mAh g‐1 at 400 mA g‐1 and maintains 193 cycles under fixed‐capacity cycling (500 mA g‐1, 500 mAh g‐1). First‐principles density functional theory (DFT) simulations demonstrate that the interfacial charge redistribution within the composite achieves an optimized LiO2 intermediate adsorption energy of ‐2.31 eV. This represents a substantial moderation compared to the overbinding strength of pristine zirconium‐based MOF and the weak adsorption exhibited by isolated reduced graphene oxide. The composite exhibits intermediate adsorption strength effectively regulates both nucleation and decomposition energetics of discharge products.

Cobalt Borate Complex With Tetrahedrally Coordinated Co2+‐ Promotes Lithium Superoxide Formation in Li‐O2 Batteries

The development of non‐aqueous lithium‐oxygen (Li‐O2) batteries is hindered by inefficient discharge product decomposition, side reactions with the electrolyte, and high charge overpotentials (>1 V). This study explores the use of sodium cobalt borate (Na3CoB5O10, NCBO) with cobalt in tetrahedral geometry as an oxygen electrocatalyst for non‐aqueous Li‐O2 batteries. The prepared cobalt borate exhibits an oxygen evolution reaction (OER) overpotential of 326 mVRHE at a current density of 10 mA cm−2 and a Tafel slope of 42 mV dec−1 in 1 m KOH. Density Functional Theory (DFT) calculations identify the OH‐covered (101) surface of NCBO as the preferred OER site, with an overpotential between 451 and 544 mV. In Li‐O2 batteries, the NCBO cathode demonstrates 200 cycles with an overpotential of 1.95 V and 56.00% round‐trip efficiency at a capacity limit of 500 mA h g−1, along with a smaller charge overpotential of 0.64 V at a capacity limit of 2000 mA h g−1. Post‐cycling analysis of NCBO electrodes reveals electronically conductive Lithium Superoxide (LiO2) as the dominant discharge product. As revealed by DFT studies, the promising performance of NCBO in Li‐O2 batteries is attributed to its tetrahedral Co coordination, highlighting its potential for electrocatalytic applications.

MOF‐Derived Bifunctional Heterojunction Electrocatalysts Embedded in Electrospun Nitrogen‐Doped Carbon Nanofibers: Binderless Efficient Freestanding Li‐CO2Mars Pouch Batteries

Li‐CO2 batteries offer a revolutionary energy storage solution, combining high specific energy with the utilization of greenhouse CO2. Although promising for applications on Earth and Mars’, the limited cycle life and significant overpotentials from stable discharge products, Li2CO3 and amorphous carbon, hinder the practicalization of Li‐CO2 batteries. To address these, we design a unique freestanding core‐shell metal‐organic framework‐derived heterojunction catalyst, Fe3O4/Co3O4, embedded in electrospun nitrogen‐doped carbon nanofibers for the Li‐CO2Mars batteries. It eliminates the need for insulating binders, toxic solvents and ensures uniformly distributed composite catalysts across the nanofibers. The electrochemical performance of Fe3O4/Co3O4/N‐doped carbon fiber (FCo/NCF)‐based Li‐CO2Mars coin cells operated in the simulated Mars’ atmosphere achieve a cycling life of 120 cycles at a current density of 50 μA cm⁻2, with a limited discharge/charge capacity of 0.1 mAh cm⁻2 and deliver a full discharge capacity of 6.8 mAh cm⁻2 outperforming the conventional catalysts. In‐situ and first‐principle studies demonstrate that enhanced CO2 adsorption and improved reversibility, driven by the bifunctional catalytic activity of FCo/NCF, lead to exceptional electrochemical performance of Li‐CO2Mars batteries. We also develop a prototype of Li‐CO2Mars pouch cell operating with an average efficiency of ~ 68 %, advancing the scalable development of Li‐CO2Mars batteries for diverse applications.

Creating Forested Wetlands for Improving Ecosystem Services and Their Potential Benefits for Rural Residents in Metropolitan Areas

Intensive farming in urban suburbs often causes habitat loss, soil erosion, wastewater discharge, and agricultural productivity decline, threatening long-term benefits for the local community. We developed a nature-based solution for sustainable land restoration by establishing “Green Treasure Island” (GTI). The aim of this study is to evaluate the ecological restoration effectiveness of GTI and explore its feasibility and replicability for future applications. The core eco-functional zone of GTI—a 7 hm2 forested wetland—embedded a closed-loop framework that integrates land consolidation, ecological restoration, and sustainable land utilization. The forested wetland efficiently removed 65% and 74% of dissolved inorganic nitrogen and phosphorus from agricultural runoff, raised flood control capacity by 22%, and attracted 48 bird species. Additionally, this biophilic recreational space attracted over 3400 visitors in 2022, created green jobs, and promoted local green agricultural product sales. Through adaptive management and nature education activities, GTI evolved into a landmark that represents local natural–social characteristics and serves as a publicly accessible natural park for both rural and urban residents. This study demonstrates the feasibility of creating GTI for improving ecosystem services, providing a practical, low-cost template that governments and local managers can replicate in metropolitan rural areas worldwide to meet both ecological and development goals.

Framework Integration for Adaptive Interfaces in Flexible Solid‐State Lithium–Oxygen Batteries

Abstract Lithium–oxygen batteries (LOBs), with their remarkable energy density, represent a pivotal advancement in energy storage technology. However, conventional Li–O2 batteries face significant obstacles. This study introduces polyacrylonitrile (PAN)‐based polymer membranes and self‐supporting cathodes fabricated via electrospinning and thermal treatment. By incorporating poly(diallyldimethylammonium chloride) (PDDA)‐functionalized cathodes through electrostatic adsorption, a polymeric electrolyte‐functional integrated linkage structure was developed. This design facilitates adaptive interface modulation, creating a stable low‐impedance interface between the electrolyte and cathode while enabling efficient ion and electron transport. The resulting solid‐state LOBs (SSLOBs) demonstrate exceptional performance, achieving a specific capacity of 8600 mAh g−1 and a cycling lifespan of 191 cycles. The adaptive interface provides abundant reaction sites, promoting uniform ring‐like discharge product growth and reversible decomposition. Additionally, flexible batteries incorporating this structure exhibit outstanding resilience to bending deformation. These advancements highlight the transformative potential of Li–O2 batteries, offering promising directions for future energy storage research.

Stabilized 2‐Electron Oxalate Mechanism Enabled by Oriented 3D Mo1.33C MXene/rGO Catalyst for Enhanced Reversibility in Flexible Li‐CO2 Batteries

Abstract The incomplete decomposition of Li2CO3 significantly impacts the reversible performance of lithium‐carbon dioxide (Li‐CO2) batteries. Current catalysts reported so far can promote the decomposition of Li2CO3 to a certain extent, but are far from sufficient, and the modulation of the discharge product to the more decomposable Li2C2O4 is a promising solution. However, Li2C2O4 exhibits insufficient stability for prolonged cycling processes. Herein, a Mo1.33C@rGO aerogel (MGA), an all‐integrated flexible cathode catalyst, is prepared for Li‐CO2 batteries, where an abundance of mobile electrons produced by the organized Mo vacancies strengthens the bonding between Mo atoms and the intermediate C2O42−, thereby stabilizing it during prolonged cycling and preventing its disproportionation into Li2CO3. At the same time, the oriented 3D framework of MGA provides ordered active sites and well‐organized electron and ion transport channels, reducing charge transfer resistance and facilitating the decomposition of Li2C2O4 with a minimal overpotential of 0.46 V, extending the cycle lifespan to 330 cycles at a current density of 20 µA cm−2. These results highlight MGA's potential as a catalyst for stabilizing intermediates and promoting Li2C2O4 decomposition, offering a promising pathway for efficient, long‐lasting, advanced Li‐CO2 batteries.

Framework Integration for Adaptive Interfaces in Flexible Solid-State Lithium-Oxygen Batteries.

Lithium-oxygen batteries (LOBs), with their remarkable energy density, represent a pivotal advancement in energy storage technology. However, conventional Li-O2 batteries face significant obstacles. This study introduces polyacrylonitrile (PAN)-based polymer membranes and self-supporting cathodes fabricated via electrospinning and thermal treatment. By incorporating poly(diallyldimethylammonium chloride) (PDDA)-functionalized cathodes through electrostatic adsorption, a polymeric electrolyte-functional integrated linkage structure was developed. This design facilitates adaptive interface modulation, creating a stable low-impedance interface between the electrolyte and cathode while enabling efficient ion and electron transport. The resulting solid-state LOBs (SSLOBs) demonstrate exceptional performance, achieving a specific capacity of 8600 mAh g-1 and a cycling lifespan of 191 cycles. The adaptive interface provides abundant reaction sites, promoting uniform ring-like discharge product growth and reversible decomposition. Additionally, flexible batteries incorporating this structure exhibit outstanding resilience to bending deformation. These advancements highlight the transformative potential of Li-O2 batteries, offering promising directions for future energy storage research.

High-Performance Aprotic Li-CO2 Battery Enabled by the Ru Heterophase Catalyst.

Aprotic Li-CO2 batteries (LCBs) hold promise for mitigating the greenhouse effect while generating electric power, yet their development remains nascent due to the sluggish CO2 activation and irreversible discharge product formation, requiring efficient catalysts to address these challenges. Herein, we developed ∼5.5 nm fcc + hcp Ru heterophase nanoparticles on a Ketjen black (KB) matrix (Rufcc+hcp/KB) as a dual-functional catalyst for LCBs. X-ray absorption spectroscopy revealed charge redistribution in the fcc + hcp heterophase and under-coordinated Ru sites, which serve as abundant active sites to boost catalytic activity. Theoretical calculations evidenced that the heterophase interface lowers the free energy barriers of the desorption of the *Li2CO3 step (*Li2CO3 → Li2CO3) and the decomposition of the *Li2C2O4 step (*Li2C2O4 → *LiC2O4 + Li), facilitating both the nucleation and decomposition of Li2CO3. Thus, the Rufcc+hcp/KB catalyst exhibited a low overpotential of 0.73 V and long-term cycling stability exceeding 2260 h (at 100 mA g-1 with a capacity of 1000 mA h g-1), outperforming Rufcc/KB (1.14 V, 1260 h), Ruhcp/KB (0.90 V, 1480 h), and previously reported Ru-based catalysts. Our findings highlight crystalline phase engineering as an effective strategy to enhance catalytic performance in LCBs.

A Liquid Metal‐Enabled Catalyst for Li‐CO2 Battery

Abstract Lithium‐carbon dioxide (Li‐CO2) batteries have recently emerged as an innovative solution for energy storage and CO2 capture, storage, and utilization. However, Li‐CO2 chemistry exhibits poor reversibility and limited cycle life due to the cathode passivation caused by insulating discharge product—Li2CO3. Herein, a liquid metal (LM)‐based catalyst anchored on reduced graphene oxide (rGO@LM@Ru) is introduced to mitigate cathode passivation and thus enhance the electrochemical performance of Li‐CO2 batteries. These findings indicate that LM plays a critical role in improving charge transfer and stabilizing the Ru catalyst on its surface. The rGO@LM@Ru cathode offers a low charge/discharge voltage gap of 1.0 V, an extended cycle life over 500 h, as well as enhanced capacity and rate performance for Li‐CO2 batteries. This work proposes a novel cathode design for CO2 redox, which suggests the promising application of the LM for next‐generation batteries.

Hierarchically Mesoporous Graphene Networks Modulate Homogeneous Two‐Electron Redox Chemistry for Highly Reversible and Stable Zinc‐Air Batteries

Abstract The emerging two‐electron (2e−) redox Zinc‐air batteries (ZABs) in neutral electrolytes have attracted substantial research interest due to their better reversibility and stability compared to alkaline ZABs. However, the generation of nonconductive discharge products (ZnO2) raises kinetics and stability challenges for the design of air cathodes. Herein, a redox‐homogenization electrochemistry approach is reported to accelerate the reversible conversion of ZnO2 and promote the 2e−/O2 reaction. The conductive graphene framework, featuring ultrahigh surface areas and high electrical/ionic conductivity, effectively reduces local current densities, thus effectively homogenizing the 2e⁻ redox reaction. Additionally, the hydrophobic 3D network not only diminishes the nucleation barrier but also restricts the growth of ZnO2 within the mesopores, achieving the homogenization of discharge products and robust reaction kinetics. The fabricated neutral ZABs exhibit a low polarization of 0.43 V and excellent stability beyond 580 h at 0.5 mA cm−2, most importantly, a benchmark energy efficiency of 75.4% at 0.1 mA cm−2 and 59.5% at 10 mA cm−2. This work provides a blueprint for constructing advanced carbon cathodes for metal‐air batteries.