10†µm-Level TiNb2 O7 Secondary Particles for Fast-Charging Lithium-Ion Batteries.

TiNb2 O7 with Wadsley-Roth phase delivers double theoretical specific capacity and similar working potential in comparison to spinel Li4 Ti5 O12 , the commercial high-rate anode material, and thus can enable much higher energy density of lithium-ion batteries. However, the inter-particle resistance within the high-mass-loading TiNb2 O7 electrode would impede the capacity release for practical application, especially under fast-charging conditions. Herein, 10-20 µm-size carbon-coated TiNb2 O7 secondary particle (SP-TiNb2 O7 ) consisting of initial micro-scale TiNb2 O7 particles (MP-TiNb2 O7 ) was fabricated. The high crystallinity of active material could enable fast-charge diffusion and electrochemical reaction rate within particles, and the small number of stacking layers of SP-TiNb2 O7 could reduce the large inter-particle resistance that regular particle electrode often possess and achieve high compaction density of electrodes with high mass loading. The investigation on materials structure and electrochemical reaction kinetics verified the advances of the as-fabricated SP-TiNb2 O7 in achieving superior electrochemical performance. The SP-TiNb2 O7 exhibited high reversible capacity of 292.7 mAh g-1 in the potential range of 1-3 V (Li+ /Li) at 0.1 C, delivering high-capacity release of 94.3 %, and high capacity retention of 86 % at 0.5 C for 250 cycles in half cell configuration. Particularly, the advances of such an anode were verified in practical 5 Ah-level laminated full pouch cell. The as-assembled LiFePO4 ||TiNb2 O7 full cell exhibited a high capacity of 5.08 Ah at high charging rate of 6 C (77.9 % of that at 0.2 C of 6.52 Ah), as well as an ultralow capacity decay rate of 0.0352 % for 250 cycles at 1 C, suggesting the great potential for practical fast-charging lithium-ion batteries.

Mitigating Concentration Polarization through Acid-Base Interaction Effects for Long-Cycling Lithium Metal Anodes.

Lithium (Li) metal has attracted great attention as a promising high-capacity anode material for next-generation high-energy-density rechargeable batteries. Nonuniform Li+ transport and uneven Li plating/stripping behavior are two key factors that deteriorate the electrochemical performance. In this work, we propose an interphase acid-base interaction effect that could regulate Li plating/stripping behavior and stabilize the Li metal anode. ZSM-5, a class of zeolites with ordered nanochannels and abundant acid sites, was employed as a functional interface layer to facilitate Li+ transport and mitigate the cell concentration polarization. As a demonstration, a pouch cell with a high-areal-capacity LiNi0.95Co0.02Mn0.03O2 cathode (3.7 mAh cm-2) and a ZSM-5 modified thin lithium anode (50 µm) delivered impressive electrochemical performance, showing 92% capacity retention in 100 cycles (375.7 mAh). This work reveals the effect of acid-base interaction on regulating lithium plating/stripping behaviors, which could be extended to developing other high-performance alkali metal anodes.

Probing Hybrid LiFePO4/FePO4 Phases in a Single Olive LiFePO4 Particle and Their Recovering from Degraded Electric Vehicle Batteries.

The recycling of LiFePO4 from degraded lithium-ion batteries (LIBs) from electric vehicles (EVs) has gained significant attention due to resource, environment, and cost considerations. Through neutron diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy, we revealed continuous lithium loss during battery cycling, resulting in a Li-deficient state (Li1-xFePO4) and phase separation within individual particles, where olive-shaped FePO4 nanodomains (5-10 nm) were embedded in the LiFePO4 matrix. The preservation of the olive-shaped skeleton during Li loss and phase change enabled materials recovery. By chemical compensation for the lithium loss, we successfully restored the hybrid LiFePO4/FePO4 structure to pure LiFePO4, eliminating nanograin boundaries. The regenerated LiFePO4 (R-LiFePO4) exhibited a high crystallinity similar to the fresh counterpart. This study highlights the importance of topotactic chemical reactions in structural repair and offers insights into the potential of targeted Li compensation for energy-efficient recycling of battery electrode materials with polyanion-type skeletons.

The dominant-substrate driven the enhanced performance in co-digestion of Pennisetum hybrid and livestock waste.

Co-digestion has been considered a promising method to improve methane yield. The effect of the proportion of dominant substrate on the performance and microbial community of anaerobic digestion of Pennisetum hybrid (PH) and livestock waste (LW) was investigated. An obvious synergistic effect was obtained with an increase of 15.20%-17.45% in specific methane yield compared to the predicted value. Meanwhile, the dominant substrate influenced the relational model between methane yield enhancement rate and mixture ratio. For the LW-dominant systems, a parabolic model between enhancement rate and mixture ratio was observed with a highest value of 392.16 mL/g VS achieved at a PH:LW ratio of 2:8. While a linear pattern appeared for PH-dominant systems with the highest methane yield of 307.59 mL/g VS. Co-digestion selectively enriched the relative abundance of Clostridium_sensu_stricto_1, Terrisporobacter, Syntrophomonas, Methanosarcina and Methanobacterium, which boosted the performance of hydrolysis, acidogenesis, acetogenesis and methanogenesis processes.

Bioaugmented ensiling of sweet sorghum with Pichia anomala and cellulase and improved enzymatic hydrolysis of silage via ball milling.

Sweet sorghum, as a seasonal energy crop, is rich in cellulose and hemicellulose that can be converted into biofuels. This work aims at investigating the effects of synergistic regulation of Pichia anomala and cellulase on ensiling quality and microbial community of sweet sorghum silages as a storage and pretreatment method. Furthermore, the combined pretreatment effects of ensiling and ball milling on sweet sorghum were evaluated by microstructure change and enzymatic hydrolysis. Based on membership function analysis, the combination of P. anomala and cellulase (PA + CE) significantly improved the silage quality by preserving organic components and promoting fermentation characteristics. The bioaugmented ensiling with PA + CE restructured the bacterial community by facilitating Lactobacillus and inhibiting undesired microorganisms by killer activity of P. anomala. The combined bioaugmented ensiling pretreatment with ball milling significantly increased the enzymatic hydrolysis efficiency (EHE) to 71%, accompanied by the increased specific surface area and decreased pore size/crystallinity of sweet sorghum. Moreover, the EHE after combined pretreatment was increased by 1.37 times compared with raw material. Hence, the combined pretreatment was demonstrated as a novel strategy to effectively enhance enzymatic hydrolysis of sweet sorghum.

Tight Binding and Dual Encapsulation Enabled Stable Thick Silicon/Carbon Anode with Ultrahigh Volumetric Capacity for Lithium Storage.

Silicon (Si) is regarded as one of the most promising anode materials for high-performance lithium-ion batteries (LIBs). However, how to mitigate its poor intrinsic conductivity and the lithiation/delithiation-induced large volume change and thus structural degradation of Si electrodes without compromising their energy density is critical for the practical application of Si in LIBs. Herein, an integration strategy is proposed for preparing a compact micron-sized Si@G/CNF@NC composite with a tight binding and dual-encapsulated architecture that can endow it with superior electrical conductivity and deformation resistance, contributing to excellent cycling stability and good rate performance in thick electrode. At an ultrahigh mass loading of 10.8 mg cm-2 , the Si@G/CNF@NC electrode also presents a large initial areal capacity of 16.7 mA h cm-2 (volumetric capacity of 2197.7 mA h cm-3 ). When paired with LiNi0.95 Co0.02 Mn0.03 O2 , the pouch-type full battery displays a highly competitive gravimetric (volumetric) energy density of ≈459.1 Wh kg-1 (≈1235.4 Wh L-1 ).

Realizing High Utilization of High-Mass-Loading Sulfur Cathode via Electrode Nanopore Regulation.

One main challenge of realizing high-energy-density lithium-sulfur batteries is low active materials utilization, excessive use of inert components, high electrolyte intake, and mechanical instability of high-mass-loading sulfur cathodes. Herein, chunky sulfur/graphene particle electrodes were designed, where active sulfur was confined in vertically aligned nanochannels (width ∼12 nm) of chunky graphene-based particles (∼70 µm) with N, O-containing groups. The short charge transport distance and low tortuosity enabled high utilization of active materials for high-mass-loading chunky sulfur/graphene particle electrodes. The intermediate polysulfide trapping effect by capillary effect and heteroatoms-containing groups, and a mechanically robust graphene framework, helped to realize stable electrode cycling. The as-designed electrode showed high areal capacity (10.9 mAh cm-2) and high sulfur utilization (72.4%) under the rigorous conditions of low electrolyte/active material ratio (∼2.5 µL mg-1) and high sulfur loading (9.0 mg cm-2), realizing high energy densities (520 Wh kg-1, 1635 Wh L-1).

LiNi0.5Mn1.5O4 Cathode Microstructure for All-Solid-State Batteries.

Solid-state batteries (SSBs) have received attention as a next-generation energy storage technology due to their potential to superior deliver energy density and safety compared to commercial Li-ion batteries. One of the main challenges limiting their practical implementation is the rapid capacity decay caused by the loss of contact between the cathode active material and the solid electrolyte upon cycling. Here, we use the promising high-voltage, low-cost LiNi0.5Mn1.5O4 (LNMO) as a model system to demonstrate the importance of the cathode microstructure in SSBs. We design Al2O3-coated LNMO particles with a hollow microstructure aimed at suppressing electrolyte decomposition, minimizing volume change during cycling, and shortening the Li diffusion pathway to achieve maximum cathode utilization. When cycled with a Li6PS5Cl solid electrolyte, we demonstrate a capacity retention above 70% after 100 cycles, with an active material loading of 27 mg cm-2 (2.2 mAh cm-2) at a current density of 0.8 mA cm-2.

Direct electrochemical generation of supercooled sulfur microdroplets well below their melting temperature.

Supercooled liquid sulfur microdroplets were directly generated from polysulfide electrochemical oxidation on various metal-containing electrodes. The sulfur droplets remain liquid at 155 °C below sulfur's melting point (Tm = 115 °C), with fractional supercooling change (Tm - Tsc)/Tm larger than 0.40. In operando light microscopy captured the rapid merging and shape relaxation of sulfur droplets, indicating their liquid nature. Micropatterned electrode and electrochemical current allow precise control of the location and size of supercooled microdroplets, respectively. Using this platform, we initiated and observed the rapid solidification of supercooled sulfur microdroplets upon crystalline sulfur touching, which confirms supercooled sulfur's metastability at room temperature. In addition, the formation of liquid sulfur in electrochemical cell enriches lithium-sulfur-electrolyte phase diagram and potentially may create new opportunities for high-energy Li-S batteries.

Manipulating Oxidation of Silicon with Fresh Surface Enabling Stable Battery Anode.

Silicon (Si)-based material is a promising anode material for next-generation lithium-ion batteries (LIBs). Herein, we report the fabrication of a silicon oxide-carbon (SiOx/C) nanocomposite through the reaction between silicon particles with fresh surface and H2O in a mild hydrothermal condition, as well as conducting carbon coating synchronously. We found that controllable oxidation could be realized for Si particles to produce uniform SiOx after the removal of the native passivation layer. The uniform oxidation and conductive coating offered the as-fabricated SiOx/C composite good stability at both particle and electrode level over electrochemical cycling. The as-fabricated SiOx/C composite delivered a high reversible capacity of 1133 mAh g-1 at 0.5 A g-1 with 89.1% capacity retention after 200 cycles. With 15 wt % SiOx/C composite, graphite-SiOx/C hybrid electrode displayed a high reversible specific capacity of 496 mAh g-1 and stable electrochemical cycling with a capacity retention of 90.1% for 100 cycles.

Manipulating Redox Kinetics of Sulfur Species Using Mott-Schottky Electrocatalysts for Advanced Lithium-Sulfur Batteries.

Lithium-sulfur (Li-S) batteries suffer from sluggish sulfur redox reactions under high-sulfur-loading and lean-electrolyte conditions. Herein, a typical Co@NC heterostructure composed of Co nanoparticles and a semiconductive N-doped carbon matrix is designed as a model Mott-Schottky catalyst to exert the electrocatalytic effect on sulfur electrochemistry. Theoretical and experimental results reveal the redistribution of charge and a built-in electric field at the Co@NC heterointerface, which are critical to lowering the energy barrier of polysulfide reduction and Li2S oxidation in the discharge and charge process, respectively. With Co@NC Mott-Schottky catalysts, the Li-S batteries display an ultrahigh capacity retention of 92.1% and a system-level gravimetric energy density of 307.8 Wh kg-1 under high S loading (10.73 mg cm-2) and lean electrolyte (E/S = 5.9 µL mgsulfur-1) conditions. The proposed Mott-Schottky heterostructure not only deepens the understanding of the electrocatalytic effect in Li-S chemistry but also inspires a rational catalyst design for advanced high-energy-density batteries.

CircFOXK2 Promotes the Progression of Osteoarthritis by Regulating the miR-4640-5p/NOTCH2 Axis.

OBJECTIVE: Osteoarthritis (OA) is the most common age-related chronic and disabling joint disease, frequently causing pain and disability in the adult population. Given that there are no proven disease-modifying drugs for OA, it is urgent to gain a deeper understanding of OA pathogenesis. This study intended to uncover the circFOXK2 regulation in OA. METHODS: Firstly, in vitro OA cell model was constructed by treating murine chondrocytes with interleukin (IL)-1ß. Then, a series of functional assays were conducted to evaluate the effect of circFOXK2 on OA progression in murine chondrocytes. Bioinformatics analysis and mechanism investigations were performed to investigate the competitive endogenous RNA (ceRNA) network of circFOXK2 in OA. RESULTS: CircFOXK2 is overexpressed in IL-1ß-treated chondrocyte. We confirmed the cyclic structure and cytoplasmic distribution of circFOXK2. Functionally, circFOXK2 promotes chondrocyte apoptosis and extracellular matrix (ECM) degradation but inhibiting chondrocyte proliferation. Mechanically, circFOXK2 competitively binds to microRNA-4640-5p (miR-4640-5p) to enhance NOTCH2 expression in OA, affecting OA progression. Besides, circFOXK2 could motivate the Notch pathway to accelerate OA progression. CONCLUSION: CircFOXK2/miR-4640-5p/NOTCH2 axis stimulates the Notch pathway to promote the transcription of inflammatory cytokines (IL33, IL17F and IL6), consequently facilitating OA progression in murine chondrocytes.

Ultrafast Metal Electrodeposition Revealed by In Situ Optical Imaging and Theoretical Modeling towards Fast-Charging Zn Battery Chemistry.

Metallic Zn is a preferred anode material for rechargeable aqueous batteries towards a smart grid and renewable energy storage. Understanding how the metal nucleates and grows at the aqueous Zn anode is a critical and challenging step to achieve full reversibility of Zn battery chemistry, especially under fast-charging conditions. Here, by combining in situ optical imaging and theoretical modeling, we uncover the critical parameters governing the electrodeposition stability of the metallic Zn electrode, that is, the competition among crystallographic thermodynamics, kinetics, and Zn2+ -ion diffusion. Moreover, steady-state Zn metal plating/stripping with Coulombic efficiency above 99 % is achieved at 10-100 mA cm-2 in a reasonably high concentration (3 M) ZnSO4 electrolyte. Significantly, a long-term cycling-stable Zn metal electrode is realized with a depth of discharge of 66.7 % under 50 mA cm-2 in both Zn||Zn symmetrical cells and MnO2 ||Zn full cells.

A Replacement Reaction Enabled Interdigitated Metal/Solid Electrolyte Architecture for Battery Cycling at 20 mA cm-2 and 20 mAh cm-2.

Metal anodes represent as a prime choice for the coming generation rechargeable batteries with high energy density. However, daunting challenges including electrode volume variation and inevitable side reactions preclude them from becoming a viable technology. Here, a facile replacement reaction was employed to fabricate a three-dimensional (3D) interdigitated metal/solid electrolyte composite electrode, which not only provides a stable host structure for buffering the volume change within the composite but also prevents side reactions by avoiding the direct contact between active metal and liquid electrolyte. As a proof-of-concept demonstration, a 3D interdigitated zinc (Zn) metal/solid electrolyte architecture was fabricated via a galvanic replacement reaction between Zn metal foil and indium (In) chloride solution followed by electrochemical activation, featuring the interdigitation between metallic Zn and amorphous indium hydroxide sulfate (IHS) with high Zn2+ conductivity (56.9 ± 1.8 mS cm-1), large Zn2+ transference number (0.55), and high electronic resistivity [(2.08 ± 0.01) × 103 Ω cm]. The as-designed Zn/IHS electrode sustained stable electrochemical Zn plating/stripping over 700 cycles with a record-low overpotential of 8 mV at 1 mA cm-2 and 0.5 mAh cm-2. More impressively, it displayed cycle-stable performance with low overpotential of 10 mV under ultrahigh current density and areal capacity (20 mA cm-2, 20 mAh cm-2), which outperformed all the reported Zn metal electrodes in mild aqueous electrolyte. The fabrication of interdigitated metal/solid electrolyte was generalized to other metal pairs, including Zn/Sn and Zn/Co, which provide inspiration for next-generation Zn metal batteries with high energy density and reversibility.

MicroRNA-139-5p Promotes Functional Recovery and Reduces Pain Hypersensitivity in Mice with Spinal Cord Injury by Targeting Mammalian Sterile 20-like Kinase 1.

Currently, there is no cure for spinal cord injury (SCI), a heavy burden on patients physiology and psychology. We found that microRNA-139-5p (miR-139-5p) expression was significantly downregulated in damaged spinal cords in mice. So, we aimed to test the effect of treatment with miR-139-5p on functional recovery and neuropathic pain in mice with SCI and investigate the underlying mechanism. The luciferase reporter assay revealed that miR-139-5p directly targeted mammalian sterile 20-like kinase 1 (Mst1), and miR-139-5p treatment suppressed Mst1 protein expression in damaged spinal cords of mice. Wild-type mice and Mst1(-/-) mice were exposed to SCI and treated with miR-139-5p agomir via intrathecal infusion. Treatment of SCI mice with miR-139-5p accelerated locomotor functional recovery, reduced hypersensitivities to mechanical and thermal stimulations, and promoted neuronal survival in damaged spinal cords. Treatment with miR-139-5p enhanced phosphorylation of adenosine monophosphate-activated protein kinase alpha (AMPKα), improved mitochondrial function, and suppressed NF-κB-related inflammation in damaged spinal cords. Deficiency of Mst1 had similar benefits in mice with SCI. Furthermore, miR-139-5p treatment did not provide further protection in Mst1(-/-) mice against SCI. In conclusion, miR-139-5p treatment enhanced functional recovery and reduced pain hypersensitivity in mice with SCI, possibly through targeting Mst1.

Conformal Prelithiation Nanoshell on LiCoO2 Enabling High-Energy Lithium-Ion Batteries.

The initial lithium loss in lithium-ion batteries (LIBs) reduces their energy density (e.g., 15% or higher for LIBs using a Si-based anode). Herein, we report in situ chemical formation of a conformal Li2O/Co nanoshell (∼20 nm) on LiCoO2 particles as a high-capacity built-in prelithiation reagent to compensate this initial lithium loss. We show a 15 mAh g-1 increase in overall charge capacity for the LiCoO2 with 1.5 wt % Li2O/Co in comparison to the pristine LiCoO2 in virtue of the irreversible lithium extraction from the nanoshell (4Li2O + 3Co → 8Li+ + 8e- + Co3O4, 2Li2O → 4Li+ + 4e- + O2↑). Paired with a graphite-SiO anode, a full cell using such a LiCoO2 cathode demonstrates 11% higher discharge capacity (2.60 mAh cm-2) than that using pristine LiCoO2 (2.34 mAh cm-2) at 0.1 C, as well as stable battery cycling. Moreover, the prelithiated LiCoO2 is compatible with the current battery fabrication process.

Metal/LiF/Li2O Nanocomposite for Battery Cathode Prelithiation: Trade-off between Capacity and Stability.

Lithium-ion batteries (LIBs) are currently dominating the portable electronics market and supplying power for electric vehicles and grid-level storage. However, lithium loss in the formation cycle at the anode side reduces the energy density of state-of-the-art LIBs with carbon anode materials. This situation will be even more severe for future LIBs using high-capacity Si-based anode materials. In this study, a transition metal-based nanocomposite with built-in lithium source was synthesized, featuring Fe nanodomains with a size of ∼5 nm uniformly dispersed in a hybrid Li2O and LiF matrix with intimate contact between them. The Fe/LiF/Li2O nanocomposite released a high Li-ion capacity of 550 mA h/g based on a multielectron inverse conversion reaction during the first-cycle charge process and exhibited better ambient stability than the counterpart with a pure Li2O matrix and also a lower lithium-extraction voltage and faster reaction kinetics than the counterpart with a pure LiF matrix. Serving as an additive to various cathodes (e.g., LiCoO2, LiFePO4, and LiNi1-x-yCoxMnyO2), the Fe/LiF/Li2O nanocomposite showed excellent lithium compensation effect. Using 4.8 wt % Fe/LiF/Li2O additive based on the total mass of the electrodes, a LiNi0.8Co0.1Mn0.1O2|SiO-graphite full cell with a high cathode mass loading of 20 mg/cm2 exhibited a high reversible capacity of 2.9 mA h/cm2 at 0.5 C after 100 cycles which is a 15% increase in comparison to the counterpart without the prelithiation additive. After the Fe/LiF/Li2O nanocomposite was immersed into the electrolyte and rested for 72 h, the content of iron metal in the electrolyte was negligible, indicating that this prelithiation additive was stable in the electrolyte and would not cause any side reactions, such as the shuttle of iron ions during cycling. The high "donor" Li-ion capacity, good ambient stability, and its compatibility with existing cathode materials and battery fabrication processes make the Fe/LiF/Li2O nanocomposite a promising cathode prelithiation additive to offset the initial lithium loss and improve the energy density of LIBs.

Electrolyte-Phobic Surface for the Next-Generation Nanostructured Battery Electrodes.

Nanostructured electrodes are among the most important candidates for high-capacity battery chemistry. However, the high surface area they possess causes serious issues. First, it would decrease the Coulombic efficiencies. Second, they have significant intakes of liquid electrolytes, which reduce the energy density and increase the battery cost. Third, solid-electrolyte interphase growth is accelerated, affecting the cycling stability. Therefore, the interphase chemistry regarding electrolyte contact is crucial, which was rarely studied. Here, we present a completely new strategy of limiting effective surface area by introducing an "electrolyte-phobic surface". Using this method, the electrolyte intake was limited. The initial Coulombic efficiencies were increased up to ∼88%, compared to ∼60% of the control. The electrolyte-phobic layer of Si particles is also compatible with the binder, stabilizing the electrode for long-term cycling. This study advances the understanding of interphase chemistry, and the introduction of the universal concept of electrolyte-phobicity benefits the next-generation battery designs.

The promotive effect of activation of the Akt/mTOR/p70S6K signaling pathway in oligodendrocytes on nerve myelin regeneration in rats with spinal cord injury.

PURPOSE: Akt/mTOR/p70S6K signaling pathway promotes motor function recovery after spinal cord injury (SCI) in both neurons and astrocytes. But the role and mechanism of this pathway in oligodendrocytes during nerve repair following SCI has not been researched. This study aimed to investigate the effect and mechanism of this signaling pathway in oligodendrocytes on nerve myelin regeneration and motor function recovery in rats with SCI. METHODS: After inhibiting or activating this signaling pathway, Western blotting and double immunofluorescence labeling were used to determine the levels of the signaling molecules in this pathway and myelin formation-related proteins in the plane of the thoracic segment of the injured spinal cord. The level of motor function recovery was evaluated and the oligodendrocytes involved in nerve myelin regeneration were studied. Primary oligodendrocytes were isolated and cultured in vitro, then MBP, PLP, and MOG were measured with reverse transcription-quantitative polymerase chain reaction (RT-qPCR). RESULTS: Akt/mTOR/p70S6K signaling pathway was activated after SCI compared with the sham-operated rats, prominently elevated levels of the pathway components were observed in the SC79-treated group. The activation of the signaling pathway significantly increased the expression levels of myelin formation-related proteins, including MBP, PLP, and MOG, and improved the Basso, Beattie, and Bresnahan (BBB) scores in the injured spinal cord. Conversely, rapamycin suppressed the expression of these signaling molecules and reduced the levels of myelin formation-related proteins. CONCLUSION: Akt/mTOR/p70S6K signaling pathway activation can contribute to nerve myelin regeneration and has the potential to improve the regenerative environment and motor function, as well as the potential to promote repair of SCI.

Revealing Nanoscale Passivation and Corrosion Mechanisms of Reactive Battery Materials in Gas Environments.

Lithium (Li) metal is a high-capacity anode material (3860 mAh g-1) that can enable high-energy batteries for electric vehicles and grid-storage applications. However, Li metal is highly reactive and repeatedly consumed when exposed to liquid electrolyte (during battery operation) or the ambient environment (throughout battery manufacturing). Studying these corrosion reactions on the nanoscale is especially difficult due to the high chemical reactivity of both Li metal and its surface corrosion films. Here, we directly generate pure Li metal inside an environmental transmission electron microscope (TEM), revealing the nanoscale passivation and corrosion process of Li metal in oxygen (O2), nitrogen (N2), and water vapor (H2O). We find that while dry O2 and N2 (99.9999 vol %) form uniform passivation layers on Li, trace water vapor (∼1 mol %) disrupts this passivation and forms a porous film on Li metal that allows gas to penetrate and continuously react with Li. To exploit the self-passivating behavior of Li in dry conditions, we introduce a simple dry-N2 pretreatment of Li metal to form a protective layer of Li nitride prior to battery assembly. The fast ionic conductivity and stable interface of Li nitride results in improved battery performance with dendrite-free cycling and low voltage hysteresis. Our work reveals the detailed process of Li metal passivation/corrosion and demonstrates how this mechanistic insight can guide engineering solutions for Li metal batteries.