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To fabricate ceramic composite cathodes LiCoO2–Li6.6La3Zr1.6Ta0.4O12 (LCO-LLZTO) on an industrial scale, a water-based tape-casting process was developed, which is scalable and environmentally friendly. Additionally, the cosintering behavior of the two materials, often leading to poor electrochemical performance, was optimized via a Li2O-rich atmosphere. The resulting dense, free-standing, and phase-pure LCO-LLZTO mixed cathodes were assembled into full cells using a dual-layer solid polymer-ceramic separator and an In–Li anode. These cells show very high utilization rates for LCO of approximately 90% at a high areal capacity of over 3 mAh cm–2, demonstrating the potential of water-based tape-casting for a scalable and sustainable manufacturing of oxide-ceramic based solid-state Li batteries.

Journal of materials chemistry / A 9(8), 4831-4840 (2021). doi:10.1039/D0TA11096E, Published by Royal Soceity of Chemistry, London [u.a.]

The garnet-type Li

The garnet-type Li7La3Zr2O12 (LLZO) ceramic solid electrolyte combines high Li-ion conductivity at room temperature with high chemical stability. Several all-solid-state Li batteries featuring the LLZO electrolyte and the LiCoO2 (LCO) or LiCoO2–LLZO composite cathode were demonstrated. However, all batteries exhibit rapid capacity fading during cycling, which is often attributed to the formation of cracks due to volume expansion and the contraction of LCO. Excluding the possibility of mechanical failure due to crack formation between the LiCoO2/LLZO interface, a detailed investigation of the LiCoO2/LLZO interface before and after cycling clearly demonstrated cation diffusion between LiCoO2 and the LLZO. This electrochemically driven cation diffusion during cycling causes the formation of an amorphous secondary phase interlayer with high impedance, leading to the observed capacity fading. Furthermore, thermodynamic analysis using density functional theory confirms the possibility of low- or non-conducting secondary phases forming during cycling and offers an additional explanation for the observed capacity fading. Understanding the presented degradation paves the way to increase the cycling stability of garnet-based all-solid-state Li batteries.

Studying the failure mechanism of methane hydrate specimens (MHSs) is of great significance to the exploitation of methane hydrate. Most previous studies have focused on the macro or micromechanical response of MHS under different conditions. However, there are a few studies that have investigated the mechanical response mechanism of MHS based on energy evolution. Therefore, in this study, a numerical model of the methane hydrate-bearing sediments was constructed in the particle flow code (PFC) environment. Then, the numerical model was validated using the conducted laboratory tests; and a series of numerical tests were conducted under different methane hydrate saturation conditions, and the obtained results were analyzed. These results qualitatively describe the main mechanical properties of the methane hydrate-bearing sediments from the viewpoint of energy evolution. The simulation results indicated that during the shear test, the bond breaks at first. Then, the soil particles (sediments) start to roll and rarely slid before shear strength arrives at the highest value. Around the highest shear strength value, more soil particles begin to roll until they occlude with each other. Strain softening is induced by the combined action of the breakage of the hydrate bond and the slipping of soil particles. The higher the hydrate saturation is, the more obvious the strain softening is. Considering that a good agreement was observed between the numerical simulation results and the laboratory test results, it can be concluded that the numerical simulation approach can complement the existing experimental techniques, and also can further clarify the deformation and failure mechanism of various methane hydrate-bearing sediments. The results obtained from the present study will contribute to a better understanding of the mechanical behavior of the gas hydrate-bearing sediments during hydrate dissociation and gas exploitation.

Redox flow batteries are promising devices for large-scale stationary energy storage. One remaining challenge towards their broad application is the rational selection of electrolyte components, composed of redox-active species, and the supporting reaction media. Particularly, good compatibility among the different components should be addressed. Compared to transition metal-based redox electrolytes, green and sustainable organic redox-active materials are becoming favourable due to their low cost, structural diversity and possibly higher volumetric capacity. Herein, we study a hydroquinone species, 2-[(2,5-dihydroxyphenyl)sulfanyl]ethan-1-aminium chloride (SEAHQ), which has high solubility in water, but rather poor chemical and electrochemical stability. Such properties preclude its practical applications. To remove such limitations, we shed light on the unique role of the aqueous supporting electrolytes. Ionic liquids, widely investigated as green reaction media, contain commonly used organic cationic groups and may have better affinity with organic redox materials. This is successfully demonstrated by combining water-soluble imidazolium-based ionic liquids and SEAHQ. Electrochemical characterization experiments showed excellent stability and reversibility of SEAHQ in the studied supporting electrolytes. Redox flow cell tests using SEAHQ as the catholyte with concentrations up to 1 M revealed high cycling efficiencies with current densities up to 100 mA cm−2 over 100 cycles. It is considered that the capacity loss over cycling is related to a continuous decrease in the utilization of the electrolytes, rather than a structural degradation of SEAHQ.

The deep water overflow at three gaps in the Heng-Chun Ridge of the Luzon Strait is investigated based on long-term continuous mooring observations. For the first time, these observations enable us to assess the detailed structure and variability in the deep water overflow directly spilling into the South China Sea (SCS). The strong bottom-intensified flows at moorings WG2 and WG3 intrude into the deep SCS with maximum along-stream velocities of 19.2 ± 9.9 and 15.2 ± 6.8 cm s−1, respectively, at approximately 50 m above the bottom. At mooring WG1, the bottom current revealed spillage into the Luzon Trough from the SCS. The volume transport estimates are 0.73 ± 0.08 Sv at WG2 and 0.45 ± 0.02 Sv at WG3, suggesting that WG2 is the main entrance for the deep water overflow crossing the Heng-Chun Ridge into the SCS. By including the long-term observational results from previous studies, the pathway of the deep water overflow through the Luzon Strait is also presented. In addition, significant intraseasonal variations with dominant time scales of approximately 26 days at WG2 and WG3 have been revealed, which tend to be enhanced in spring and may reverse the deep water overflow.

Garnet‐based Li‐ion conductors are one of the most promising oxide‐ceramic solid electrolytes for next‐generation Li batteries. However, they undergo a Li+/H+ exchange (LHX) reaction with most protic solvents used in component manufacturing routes and even with moisture in ambient air. These protonated garnets show a lower Li‐ionic conductivity, and even if only the surface is protonated, this degraded layer hinders the Li‐ion exchange with, for example, a metallic Li anode. Furthermore, the resulting unstable surface properties during the processing in air lead to challenges with respect to reproducibility of the final component performance, limiting their commercial applicability. However, in recent years, the knowledge about the underlying chemical mechanisms has led to the development of mitigation strategies and enabled a push of this promising material class towards sustainable and scalable fabrication routes. This Minireview covers the following four aspects, which are relevant for a comprehensive understanding of these developments: (1) reports of LHX phenomenon in garnets exposed to air and solvents; (2) recent understandings of the fundamentals and properties of LHX; (3) strategies to prevent LHX and to recover garnets; and (4) sustainable application of LHX for material processing and energy‐related devices., Garnet conductors: Li+/H+ exchange reaction, which causes low ionic conductivity and surface degradation, has been considered as a disadvantage of garnet‐based Li+‐conductors. However, the recent knowledge about the underlying chemical mechanisms has led to the development of mitigation strategies and enabled a push of this promising material class towards sustainable and scalable fabrication routes and energy‐related applications.

Garnet-based all-solid-state lithium batteries (ASSLB) provide high intrinsic safety, extended operational temperature range, and high energy density. As the first two are intrinsic to the materials system, one prerequisite to obtain high energy densities with such ASSLBs is the manufacturing of composite cathodes. Preferably, cathode active material (CAM) and electrolyte should form an intertwined 3D-network with an intimate extended contact between two phases. The interface between the CAM and the electrolyte should feature high total surface area with a low impedance to enable an efficient charge transfer and transport and minimize the resistance losses in a battery. Composite solid cathode microstructures can be formed via a co-sintering of solid electrolyte and CAM powders. However, many CAMs such as Li[Ni1-x-yCoxMny]O2 (NMC), Li[Ni1-x-yCoxAly]O2 (NCA) or Li2NiMn3O8 (LMO) cannot withstand sintering temperatures required, for oxide class solid electrolytes as Li7La3Zr2O12 (LLZ) or Li1+xAlxTi2-x(PO4)3, to obtain sintered composite cathodes. Furthermore, the thermodynamic stability of CAMs significantly decreases in the presence of solid electrolytes. Still, several groups have demonstrated that thermodynamic limitations can be significantly lessened via a kinetic control of the process such as reduction of reaction times and a careful control of powder morphology during ceramic sintering process. Following this work, we demonstrate that Field Assisted Sintering Technique / Spark Plasma Sintering (FAST/SPS) enables fabrication of different functional solid-state battery components within minutes such as dense LLZ separator layers with a high ionic conductivity, thick LiCoCO2 (LCO)/LLZ composite cathodes without any interfacial reactions, and integrated cathode half-cells consisting of a composite cathode and a LLZ separator layer at temperatures as low as 675 °C. . The analysis of these composite cathodes revealed well sintered pure phases and a homogenous distribution of cubic LLZ and cathode active material. Electrochemical tests showed promising electronic and ionic conductivity (0.4 mS cm-1) values and an increased capacity (4 mA cm-2) compared to cathodes with pure active material. The structural analysis after the electrochemical characterization shows the mechanical integrity of the LLZ/LCO interface, which means that a mechanically stable rigid LLZ/LCO interface can be obtained. Such a mechanically stable LLZ/LCO cathode allows to analyze possible electrochemistry induced degradation, which is suggested by theoretical work but lacks experimental validation. A detailed analysis of the LLZ/LCO interface by SEM, TEM, Raman, and XRD provide insights into the processes occurring during electrochemical cycling. The findings can pave the way to increase the cycling stability of ceramic all-solid-state batteries via interface optimization Figure 1

All-solid-state lithium batteries (ASSLBs) can potentially outperform conventional Li-ion batteries with liquid or polymer electrolyte. One example for solid electrolytes is the garnet-type oxide Li7La3Zr2O12 (LLZO). LLZO has a wide electrochemical window, stability vs. lithium, and good ionic conductivity at room temperature. The cathode in ASSLBs is manufactured from a cathode active material (CAM), such as LiCoO2 (LCO). The efficiency of Li-ion storage can be improved by the use of a composite cathode consisting from a CAM and an ion-conducting ceramic, e.g. LCO/LLZO. In such a composite cathode, LLZO delivers Li-ions through the whole bulk enhancing the volumetric loading of LCO. In this work the addition of polymer electrolyte into LCO/LLZO composite cathode was proposed, aiming at further increase of cell performance due to facilitation of CAM usage, similar to the approach of manufacturing of polymer-ceramic electrolytes. They are fabricated mostly by tape casting of slurry with polymer matrix, ceramic filler and a solvent. An alternative technology includes free sintering of tape-casted LCO/LLZO porous network and subsequent infiltration by liquid or polymer electrolyte. Free sintering of LCO/LLZO composite requires relatively high temperature and/or long sintering time. This results in loss of volatile Li with decrease in electrochemical performance. In the present work the LCO/LLZO composite cathode was manufactured in a powder-based process by Field-Assisted Sintering Technique also known as Spark Plasma Sintering (FAST/SPS). Fast heating (100°C/min and higher) and application of mechanical pressure during FAST/SPS enable reduction of sintering temperature and processing time needed for fabrication of nearly-fully-dense composite.[1] Thereby, Li evaporation and grain growth can be significantly reduced. This technology was used in our previous work for fabrication of half-cells with dense LLZO electrolyte and dense LCO/LLZO composite cathode. However, the appearance of side phase after sintering at low pressure and a residual porosity was observed. The reason for that was partial reduction of oxides by carbon originated from graphite foil in FAST/SPS setup. In the presented work, the graphite foil was replaced by carbon-free mica foil. This measure enabled FAST/SPS sintering of porous LCO/LLZO network without side phase formation. The obtained porous skeleton was infiltrated with polymer electrolyte to fabricate a polymer-ceramic composite cathode. The cathode was assembled with an anodic half-cell consisting of dense FAST/SPS-sintered LLZO electrolyte and attached indium (In) foil used as anode. The ASSLB with polymer-ceramic composite cathode showed significantly lower interfacial impedance and remarkably higher area-specific storage capacity as compared to the similar ASSLBs with pure ceramic (porous or dense) composite cathodes. Thus, the functionality and the advanced storage capacity of the proposed polymer-ceramic cathode and related ASSLB architecture were demonstrated.[2] References: [1] M. Ihrig, M. Finsterbusch, C.-L. Tsai, A.M. Laptev, C.-h. Tu, M. Bram, Y.J. Sohn, R. Ye, S. Sevinc, S.-k. Lin, D. Fattakhova-Rohlfing, O. Guillon, Journal of Power Sources, 482 (2021) 228905. [2] M. Ihrig, R. Ye, A.M. Laptev, D. Grüner, R. Guerdelli, W.S. Scheld, M. Finsterbusch, H.-D. Wiemhöfer, D. Fattakhova-Rohlfing, O. Guillon, ACS Applied Energy Materials, 4 (2021) 10428-10432. Figure 1

Polymer–ceramic all-solid-state Li batteries (ASSLBs) combine the advantages of fully inorganic and polymer-based ASSLBs. In particular, the application of proposed polymer–ceramic composite cathodes could be essential for the enhancement of the energy storage capacity of ASSLBs. The use of a modified field-assisted sintering technique with adjustable pressure and with alternative mica foil enables the fabrication of porous cathodes at a reduced sintering temperature and without side phase formation. This allows sintering of a porous LiCoO2/Li7La3Zr2O12:Ta composite network suitable for polymer infiltration and assembly in an ASSLB from the cathode side. The ceramic LiCoO2/Li7La3Zr2O12:Ta composite cathodes infiltrated with an ion-conducting polymer have shown an enhanced areal storage capacity.

ChemSusChem : chemistry & sustainability, energy & materials (2021). doi:10.1002/cssc.202101178 special issue: "Chemistry Europe Reviews", Published by Wiley-VCH, Weinheim

One of the necessary prerequisites to advance the electrochemical performance of Li7La3Zr2O12 (LLZ) based all-solid-state lithium batteries is the manufacturing of dense composite cathodes from cathode active material (CAM) and the LLZ ceramic solid electrolyte. However, free co-sintering of LLZ and CAM mixtures requires temperatures above 1000 °C which often leads to decomposition and secondary phase formation, especially for high energy CAMs. In our study we present a completely dry processing route which is fast, free of any sintering additives and coatings and suitable to fabricate dense mixed cathodes, pure LLZ separators and multilayers of the two. Through application of high mechanical pressure during Field-Assisted Sintering we were able to reduce the sintering temperature down to 675–750 °C with dwell times as low as 10 min, while still obtaining 95% theoretical density for LCO/LLZ mixtures. The low sintering temperature is suitable for high energy CAMs, but leads to a significant effect of surface impurities, especially from powder handling in air, and affects the crystallinity of the CAM/LLZ interface. In the present paper we investigate the impact of resulting interfaces on the ionic conductivity, the interfacial impedance and the cycling stability of produced cells and propose the optimization strategy.

All-solid-state sodium batteries (ASSNBs), which combine the benefits of high safety and low cost, are expectedto be an alternative or complementary storage technology to lithium ion batteries. Herein, we developed anaqueous tape casting technique for the continuous fabrication of ceramic sheets made of silicate-based Na5YSi4O12(NYS) Na+ ion superionic conductor for the first time. After sintering, the ceramics showed a total conductivityof 1.0 mS cm􀀀 1 at room-temperature, low total activation energy of 0.30 eV, and wide electrochemicalwindow of over 8 V. The critical current density of NYS tape against Na-metal electrodes can reach 2.2 mA cm􀀀 2and the galvanostatic cycling time is over 280 h under 0.8 mA cm􀀀 2 and 0.8 mAh cm􀀀 2. The obtained tape hashigh crystalline purity, dense microstructure, favorable mechanical properties (hardness H of 2 GPa and elasticmodulus E of 45 GPa). This work not only highlights the potential of the scarcely studied silicate-based NYS ionicconductor as a functional separator, but also presents a cost-efficient and eco-friendly continuous fabricationusing the aqueous tape casting technique, thus being expected to boost the practical application of NYS as solidstateelectrolyte in ASSNBs.

Several hydrophilic ionic liquids dissolved in water with different molalities are studied as “water-in-ionic liquid” supporting electrolytes. They exhibit wide electrochemical stability window from 3 to 4.4 V, high ionic conductivities and good flowability, making them promising supporting electrolytes for aqueous high-voltage rechargeable batteries. In such supporting electrolytes, enhanced redox activities of lithium insertion/extraction in anodic TiO2 film at low negative potential and Fe3+/Fe2+ couple at moderate positive potential were observed. Cyclability of an aqueous TiO2/Fe2+ hybrid battery is demonstrated with a voltage of 1.7 V.

Internal solitary waves (ISWs) can cause strong vertical and horizontal currents and turbulent mixing in the ocean. These processes affect sediment and pollutant transport, acoustic transmissions and man-made structures in the shallow and deep oceans. Previous studies of the role of ISWs in suspending seafloor sediments and forming marine nepheloid layers were mainly conducted in shallow-water environments. In summer 2017, we observed at least four thick (70-140 m) benthic nepheloid layers (BNLs) at water depths between 956 and 1545 m over continental slopes in the northern South China Sea. We found there was a good correlation between the timing of the ISW packet and variations of the deepwater suspended sediment concentration (SSC). At a depth of 956 m, when the ISW arrived, the near-bottom SSC rapidly increased by two orders of magnitude to 0.62 mg/l at 8 m above the bottom. At two much deeper stations, the ISW-induced horizontal velocity reached 59.6-79.3 cm/s, which was one order of magnitude more than the seafloor contour currents velocity. The SSC, 10 m above the sea floor, rapidly increased to 0.10 mg/l (depth of 1545 m) and 1.25 mg/l (depth of 1252 m). In this study, we found that ISWs could suspend much more sediments on deepwater areas than previously thought. Specifically, we estimated that ISWs could induce and suspend 78.7 Mt/yr of sediment from shelf to deep-sea areas of the northern South China Sea. The total amount of sediment resuspended by shoaling ISWs was 2.7 times that of river-derived sediment reaching the northern South China Sea. This accounted for 6.1% of the global river-discharged sediment (16.4% of that from Asian rivers) transported to the sea.

Internal solitary waves (ISWs) can cause strong vertical and horizontal currents and turbulent mixing in the ocean. These processes affect sediment and pollutant transport, acoustic transmissions and man-made structures in the shallow and deep oceans. Previous studies of the role of ISWs in suspending seafloor sediments and forming marine nepheloid layers were mainly conducted in shallow-water environments. In summer 2017, we observed at least four thick (70–140 m) benthic nepheloid layers (BNLs) at water depths between 956 and 1545 m over continental slopes in the northern South China Sea. We found there was a good correlation between the timing of the ISW packet and variations of the deepwater suspended sediment concentration (SSC). At a depth of 956 m, when the ISW arrived, the near-bottom SSC rapidly increased by two orders of magnitude to 0.62 mg/l at 8 m above the bottom. At two much deeper stations, the ISW-induced horizontal velocity reached 59.6–79.3 cm/s, which was one order of magnitude more than the seafloor contour currents velocity. The SSC, 10 m above the sea floor, rapidly increased to 0.10 mg/l (depth of 1545 m) and 1.25 mg/l (depth of 1252 m). In this study, we found that ISWs could suspend much more sediments on deepwater areas than previously thought. Specifically, we estimated that ISWs could induce and suspend 787 Mt/yr of sediment from shelf to deep-sea areas of the northern South China Sea. The total amount of sediment resuspended by shoaling ISWs was 2.7 times that of river-derived sediment reaching the northern South China Sea. This accounted for 6.1% of the global river-discharged sediment (16.4% of that from Asian rivers) transported to the sea.

The South China Sea (SCS) is the largest marginal sea in the northwest Pacific Ocean. In this study, deep circulation in the SCS is investigated using results from eddy-resolving, regional simulations using the Hybrid Coordinate Ocean Model (HYCOM) verified by continuous current-meter observations. Analysis of these results provides a detailed spatial structure and temporal variability of the deep circulation in the SCS. The major features of the SCS deep circulation are a basin-scale cyclonic gyre and a concentrated deep western boundary current (DWBC). Transport of the DWBC is ∼ 2 Sv at 16.5° N with a width of ∼53 km. Flowing southwestward, the narrow DWBC becomes weaker with a wider range. The model results reveal the existence of 80- to 120-day oscillation in the deep northeastern circulation and the DWBC, which are also the areas with elevated eddy kinetic energy. This intraseasonal oscillation propagates northwestward with a velocity amplitude of ∼ 1.0 to 1.5 cm s-1. The distribution of mixing parameters in the deep SCS plays a role in both spatial structure and volume transport of the deep circulation. Compared with the northern shelf of the SCS with the Luzon Strait, deep circulation in the SCS is more sensitive to the large vertical mixing parameters of the Zhongsha Island Chain area.

Various dismutative structures of the form [E(EX)(EX2)]2 with E being C, Si, and/or Ge and X being some side group (H, CH3, F, or Cl) were studied with the special purpose of identifying signals for aromaticity in those compounds. Also a dismutative analogue of pyridine was studied. In order to identify signals of aromaticity we focused on the total energy, the HOMO–LUMO energy gap, the variation of the nearest-neighbour bond lengths along the backbone, and NICS and NICSzz as functions of the distance along a normal to a plane of the molecule. In many cases, strong distortions from a nearly-planar structure were observed. Only in few cases, the bond lengths could suggest the existence of aromaticity or anti-aromaticity. On the other hand, in many cases NICS and NICSzz give signals that suggest the existence of aromaticity similar to that of spherical cluster compounds.

The garnet-type Li-ion-conductor Li7La3Zr2O12 (LLZO) is regarded as a promising oxide-ceramic based solid electrolyte (SE) material for all-solid-state lithium ion battery (Li-ASB) owing to its wide electrochemical stability window, chemical stability versus Li metal and excellent conductivity. However, one of the challenges regarding the fabrication of such ASBs is the industrial scalability of manufacturing methods. Tape-casting of ceramic components is known e.g. from SOFC manufacturing to enable the large-scale production of free-standing ceramic components and cells with low thickness. Additionally, in conventional tape-casting, organic solvents are usually employed, which give rise to health and safety issues and lead to high cost for solvent recovery. Hence, development of a green, water-based processing route is favorable. Herein, we report an aqueous tape-casting process of LLZO separators using a water-soluble biopolymer as binder. A lattice expansion of LLZO is observed by X-ray diffraction in aqueous green tape due to the partial replacement of Li+ by H+, whereas the lattice parameter of LLZO in sintered sheet decreases to the same value of pristine LLZO powder, indicating the Li-recovery in the LLZO structure after sintering. This observation confirms that the Li+/H+-exchange reaction is reversible during the aqueous processing. The obtained free-standing LLZO sheet after sintering shows high ionic conductivity observed by impedance spectrometry in Li/LLZO/Li symmetric cell at room temperature, which is comparable with reported thin garnet separators fabricated by conventional non-aqueous tape-casting. In summary, we successfully fabricate self-supporting LLZO sheet with high ionic conductivity by aqueous tape-casting process, which is enabled by reversible Li+/H+-exchange. This free-standing LLZO sheet can be later used as separator in the Li-ASBs having an electrolyte-supported configuration.

The utilization of intermittent renewable energy sources needs low-cost, reliable energy storage systems in the future. Among various electrochemical energy storage systems, redox flow batteries (RFBs) are promising with merits of independent energy storage and power generation capability, localization flexibility, high efficiency, low scaling-up cost, and excellent long charge/discharge cycle life. RFBs typically use metal ions as reacting species. The most exploited types are all-vanadium RFBs (VRFBs). Here, we discuss the core components for the VRFBs, including the development and application of different types of membranes, electrode materials, and stack system. In addition, we introduce the recent progress in the discovery of novel electrolytes, such as redox-active organic compounds, polymers, and organic/inorganic suspensions. Versatile structures, tunable properties, and abundant resources of organic-based electrolytes make them suitable for cost-effective stationary applications. With the active species in solid form, suspension electrolytes are expected to provide enhanced volumetric energy densities.

The DNA sensing pathway triggers innate immune responses against DNA virus infection, and NF-κB signaling plays a critical role in establishing innate immunity. We report here that the herpes simplex virus 1 (HSV-1) ubiquitin-specific protease (UL36USP), which is a deubiquitinase (DUB), antagonizes NF-κB activation, depending on its DUB activity. In this study, ectopically expressed UL36USP blocked promoter activation of beta interferon (IFN-β) and NF-κB induced by cyclic GMP-AMP synthase (cGAS) and stimulator of interferon genes (STING). UL36USP restricted NF-κB activation mediated by overexpression of STING, TANK-binding kinase 1, IκB kinase α (IKKα), and IKKβ, but not p65. UL36USP was also shown to inhibit IFN-stimulatory DNA-induced IFN-β and NF-κB activation under conditions of HSV-1 infection. Furthermore, UL36USP was demonstrated to deubiquitinate IκBα and restrict its degradation and, finally, abrogate NF-κB activation. More importantly, the recombinant HSV-1 lacking UL36USP DUB activity, denoted as C40A mutant HSV-1, failed to cleave polyubiquitin chains on IκBα. For the first time, UL36USP was shown to dampen NF-κB activation in the DNA sensing signal pathway to evade host antiviral innate immunity. IMPORTANCE It has been reported that double-stranded-DNA-mediated NF-κB activation is critical for host antiviral responses. Viruses have established various strategies to evade the innate immune system. The N terminus of the HSV-1 UL36 gene-encoded protein contains the DUB domain and is conserved across all herpesviruses. This study demonstrates that UL36USP abrogates NF-κB activation by cleaving polyubiquitin chains from IκBα and therefore restricts proteasome-dependent degradation of IκBα and that DUB activity is indispensable for this process. This study expands our understanding of the mechanisms utilized by HSV-1 to evade the host antiviral innate immune defense induced by NF-κB signaling.