Ultrahigh Areal Capacitance Research Articles

Large-scale vertical graphene on nickel foil as a binder-free electrode for high performance battery-like supercapacitor with an aqueous redox electrolyte

Due to the special three-dimensional structures and excellent physicochemical properties, vertical graphene (VG) has been extensively investigated as potential material for supercapacitors. However, achieving VG-based supercapacitors with high-energy density and high-power density is a still tremendous challenge. Here we attempt to synthesize large-scale VG films on flexible substrates and design a novel battery-like supercapacitor (BSCs) with the VG on Ni foil (VG@Ni) as a binder-free electrode operating in the KOH electrolyte with the redox additives of K3Fe(CN)6 and/or K4Fe(CN)6. The VG@Ni electrodes demonstrate an ultrahigh areal capacitance of 1453 mF cm−2 at 5 mA cm−2 in 1 M KOH electrolyte with adding 0.07 M K3Fe(CN)6 and 0.07 M K4Fe(CN)6, coulombic efficiency greater than 90%, and long-life cycling stability (capacitance retention is 99.3% after 20000 charge-discharge cycles). The BSCs, which are assembled with two identical VG@Ni electrodes, deliver the areal capacitance of 231 mF cm−2 with energy density of 32 μWh cm−2 and power density of 2498 μW cm−2 at 1 mA cm−2. These outstanding performances can be ascribed to the special feature and excellent properties of VG materials, high electronic conductivity of binder-free VG@Ni electrode, faradaic properties of redox electrolyte, and synergistic effects between the VG film and redox electrolyte.

Three-dimensionally multiple protected silicon anode toward ultrahigh areal capacity and stability

Silicon (Si) is considered as one of the most promising candidates for next-generation lithium-ion battery (LIB) anode due to its high theoretical capacity. However, the drastic volume change of Si anodes during lithiation/delithiation processes leads to rapid capacity fade. Herein, a three-dimensional Si anode with multiple protection strategy is proposed, including citric acid-modification of Si particles (CA@Si), GaInSn ternary liquid metal (LM) addition, and porous copper foam (CF) based electrode. The CA modified supports strong adhesive attraction of Si particles with binder and LM penetration maintains good electrical contact of the composite. The CF substrate constructs a stable hierarchical conductive framework, which could accommodate the volume expansion to retain integrity of the electrode during cycling. As a result, the obtained Si composite anode (CF-LM-CA@Si) demonstrates a discharge capacity of 3.14 mAh cm−2 after 100 cycles at 0.4 A g−1, corresponding to 76.1% capacity retention rate based on the initial discharge capacity and delivers comparable performance in full cells. The present study provides an applicable prototype of high-energy density electrodes for LIBs.

High-performance Zn-ion hybrid supercapacitors enabled by rationally designed hierarchical SiC@C quasi-aligned nanoarrays

In the present work, we report the exploration of rationally designed electrodes based on quasi-aligned nanoarrays composited by the cores of SiC nanowires and shells of sulfur-doped porous carbons (SiC@PC-S), which are directly employed as the free-standing electrodes for Zn-ion hybrid supercapacitors. They behave an ultrahigh areal capacitance of 38.24 mF/cm2 at a scan rate of 10 mV/s, with an exceptional rate capability (~20.67 mF/cm2 even at 1000 mV/s). The as-constructed hybrid supercapacitors deliver a remarkable energy of 10.6 μWh/cm2, which is the highest one among SiC-based supercapacitors ever reported. Moreover, such hybrid devices exhibit a high power density of 7.2 mW/cm2 and a robust cycle stability with ~97 % capacitance retention after 5000 cycles at 2 mA/cm2, representing their promising practical applications.

Hierarchical Columnar Cactus-like Co-MOF@NiCo-LDH Core–Shell Nanowrinkled Pillar Arrays for Supercapacitors with Ultrahigh Areal Capacitance

The design of metal–organic framework/layered double hydroxide (MOF/LDH) heterogeneous hybrids is crucial to the enhancement of areal capacitance for supercapacitor electrodes. Herein, the NiCo-LDH nanowrinkles are evenly epitaxially grown on the surface of self-supported Co-MOF nanoneedles to form aligned nanopillar arrays by a facile electrodeposition. Thanks to the high porosity of the Co-MOF, excellent redox activity of NiCo-LDH, and interfacial synergy of the core–shell multicomponent heterostructure, the Co-MOF@NiCo-LDH composite has an extraordinary areal capacitance (44.1 F cm–2 at 5 mA cm–2), which is 7.6 and 2.6 times higher than that of the bare NiCo-LDH and Co-MOF, respectively. Furthermore, the constructed asymmetric supercapacitor with activated carbon demonstrates a satisfactory energy density of 0.89 mWh cm–2 at the power density of 7.5 mW cm–2 and superior cycling stability (97.6% capacitance retention after 10,000 cycles).

A 3D-Printed Proton Pseudocapacitor with Ultrahigh Mass Loading and Areal Energy Density for Fast Energy Storage at Low Temperature.

The sluggish ionic transport in thick electrodes and freezing electrolytes has limited electrochemical energy storage devices in lots of harsh environments for practical applications. Here, a 3D-printed proton pseudocapacitor based on high-mass-loading 3D-printed WO3 anodes, Prussian blue analog cathodes, and anti-freezing electrolytes is developed, which can achieve state-of-the-art electrochemical performance at low temperatures. Benefiting from the cross-scale 3D electrode structure using a 3D printing direct ink writing technique, the 3D-printed cathode realizes an ultrahigh areal capacitance of 7.39Fcm-2 at a high areal mass loading of 23.51mgcm-2 . Moreover, the 3D-printed pseudocapacitor delivers an areal capacitance of 3.44 Fcm-2 and excellent areal energy density (1.08 mWhcm-2 ). Owing to the fast ion kinetics in 3D electrodes and the high ionic conductivity of the hybrid electrolyte, the 3D-printed supercapacitor delivers 61.3% of the room-temperature capacitance even at -60°C. This work provides an effective strategy for the practical applications of energy storage devices with complex physical structure at extreme temperatures.

Superstructured NiMoO4@CoMoO4 core-shell nanofibers for supercapacitors with ultrahigh areal capacitance

High areal capacitance for a practical supercapacitor electrode requires both large mass loading and high utilization efficiency of electroactive materials, which presents a great challenge. Herein, we demonstrated the unprecedented synthesis of superstructured NiMoO4@CoMoO4 core-shell nanofiber arrays(NFAs) on a Mo-transition-layer-modified nickel foam (NF) current collector as a new material, achieving the synergistic combination of highly conductive CoMoO4 and electrochemical active NiMoO4. Moreover, this superstructured material exhibited a large gravimetric capacitance of 1,282.2 F/g in 2 M KOH with a mass loading of 7.8 mg/cm2, leading to an ultrahigh areal capacitance of 10.0 F/cm2 that is larger than any reported values of CoMoO4 and NiMoO4 electrodes. This work provides a strategic insight for rational design of electrodes with high areal capacitances for supercapacitors.

Enabling 420Whkg-1 Stable Lithium-Metal Pouch Cells by Lanthanum Doping.

Lithium (Li)metal, a promising anode for high-energy-density rechargeable batteries, typically grows along the low-surface energy (110) plane in the plating process, resulting in uncontrollable dendrite growth and unstable interface. Herein, an unexpected Li growth behavior by lanthanum (La) doping is reported: the preferred orientation turns to (200) from (110) plane, enabling 2D nuclei rather than the usual 1D nuclei upon Li deposition and thus forming a dense and dendrite-free morphology even at an ultrahigh areal capacity of 10mAhcm-2 . Noticeably, La doping further decreases the reactivity of Li metal toward electrolytes, thereby establishing a stable interface. The dendrite-free, stable Li anode enables a high average Coulombic efficiency of 99.30% at 8mAhcm-2 for asymmetric Li||LaF3 -Cu cells. A 3.1Ah LaF3 -Li||LiNi0.8 Co0.1 Mn0.1 O2 pouch cell at a high energy density (425.73Whkg-1 ) with impressive cycling stability (0.0989% decaypercycle) under lean electrolyte (1.76gAh-1 ) and high cathode loading (5.77mAhcm-2 ) using this doped Li anode is further demonstrated.

Flexible quasi-solid-state zinc-ion hybrid supercapacitor based on carbon cloths displays ultrahigh areal capacitance

• A ZHSC with ultrahigh areal capacitance and long stability was demonstrated by an ACC cathode. • The ACC//Zn@ACC ZHSC device had the areal capacitance up to 2437 mF•cm −2 at 1 mA•cm −2 . • The FQSS ACC//Zn@ACC ZHSC device had high mechanical flexibility and wearable stability and output. • The energy storage mechanism was double-layer capacitive behavior of Zn 2+ accompanying dissolution/deposition of ZSO. Over the past few years, the flexible quasi-solid-state zinc-ion hybrid supercapacitors (FQSS ZHSCs) have been found to be ideal for wearable electronics applications due to their high areal capacitance and energy density. The assembly of desirable ZHSCs devices that have promising practical applications is of high importance, whereas it is still challenging to assemble ZHSCs devices. In this study, a ZHSC that exhibited ultrahigh areal capacitance and high stability was developed by using an active carbon cloth (ACC) cathode, which could improve ionic adsorption. The as-obtained ACC cathode had an energy storage mechanism due to the electrical double-layer capacitive behavior of Zn 2+ , which was accompanied by the dissolution/deposition of Zn 4 SO 4 (OH) 6 ·5H 2 O. The ACC//Zn@ACC ZHSC device exhibited an areal capacitance of 2437 mF cm −2 (81 F cm −3 , 203 F g −1 under the mass of ACC with ∼12 mg cm −2 ) at 1 mA cm −2 , an areal energy density of 1.354 mWh cm −2 at 1 mW cm −2 , as well as high stability (with an insignificant capacitance decline after 20000 cycles), which was demonstrated to outperform the existing ZHSCs. Furthermore, the assembled flexible device still had competitive capacitance, energy density and service life when integrated into a FQSS ZHSC. When applied in practice, the device could achieve high mechanical flexibility, wearable stability and output. This study can inspire the development of the FQSS ZHSC device to satisfy the demands for wearable energy storage devices with high performance.

Ferroconcrete-like multilayer VACNTs@Si film for ultra-high areal and volumetric Li-ion storage

Endowing Si-based anodes with both high areal and volumetric capacity is of great importance for their practical application, but this remains extremely challenging. Si-based anodes with high areal capacity are generally designed into porous structures to buffer the drastic volume change during charge/discharge process, which leads to a compromise in volumetric capacities. Herein, through a layer-by-layer technique, multilayer vertically aligned carbon nanotubes supported Si film (VACNTs@Si) with ferroconcrete-like sructures are developed to enhance both areal and volumetric capacities. The VACNTs frameworks facilitate electron transport and stabilize the andoe structure during cycling, while the Si cladding layer can provide a high capacity. A 3-layer VACNTs@Si film exhibits an superior areal/volumetric capacity of 3.59 mAh cm−2/3355.1 mAh cm−3, and high capacity retention of ∼79% after 200 cycles. The ferroconcrete-like structural design offers a promising strategy for the fabrication of the electrodes with ultra-high areal and volumetric capacities.

A supercapacitor electrode with ultrahigh areal capacity by using loofah-inspired bimetallic selenide-incorporated hierarchical nanowires

Nanostructure engineering on the electrodes remains challenging for high-performance supercapacitors to meet the ever-increasing demands. Inspired by the function and structure of the loofah which possesses an inner firm skeleton coupled with the outer crisscrossed fibers, herein, a novel loofah-like core-shell nanostructure is synthesized with well-designed Co0.6Mn0.4Se nanowires dominated as the core, and MnO2 nanoflakes decorated as the shell. The bimetallic selenide exhibits high conductivity and rich electrochemical activity owing to the coexisting metals component. It also serves as a robust support to hinder the agglomeration of MnO2 nanoflakes, forming a unique porous structure with great ability of self-adapting to volumetric changes. The optimized Co0.6Mn0.4Se/MnO2 electrode exhibits an ultrahigh areal capacity (3.91 F cm−2/0.60 mAh cm−2 at 2 mA cm−2) and an exceptional retention of 95.47 % after 8000 cycles. Both performances are superior to the MnCo2O4/MnO2 electrode without the loofah-like networks in our work. Moreover, the assembled Co0.6Mn0.4Se/MnO2//AC (active carbon) hybrid supercapacitor delivers a high energy density of ∼89.67 Wh kg−1 at a power density of 399.98 W kg−1, and a remarkable life span with ∼97.30 % retention after 12,000 charge/discharge cycles. The eye-catching results indicate that the integrated Co0.6Mn0.4Se nanowires show great potential to engineering advanced electrodes. Further demonstration of the all-solid-state flexible cell based on the bio-inspired Co0.6Mn0.4Se/MnO2 structure also proves its practical application in wearable electronics.

Ordered Mesoporous Carbon Grafted MXene Catalytic Heterostructure as Li-Ion Kinetic Pump toward High-Efficient Sulfur/Sulfide Conversions for Li-S Battery.

Lithium-sulfur (Li-S) batteries exhibit unparalleled theoretical capacity and energy density than conventional lithium ion batteries, but they are hindered by the dissatisfactory "shuttle effect" and the sluggish conversion kinetics owing to the low lithium ion transport kinetics, resulting in rapid capacity fading. Herein, a catalytic two-dimensional heterostructure composite is prepared by evenly grafting mesoporous carbon on the MXene nanosheet (denoted as OMC-g-MXene), serving as interfacial kinetic accelerators in Li-S batteries. In this design, the grafted mesoporous carbon in the heterostructure can not only prevent the stack of MXene nanosheets with the enhanced mechanical property but also offer a facilitated pump for accelerating ion diffusion. Meanwhile, the exposed defect-rich OMC-g-MXene heterostructure inhibits the polysulfide shuttling with chemical interactions between OMC-g-MXene and polysulfides and thus simultaneously enhances the electrochemical conversion kinetics and efficiency, as fully investigated by in situ/ex situ characterizations. Consequently, the cells with OMC-g-MXene ion pumps achieve a high cycling capacity (966 mAh g-1 at 0.2 C after 200 cycles), a superior rate performance (537 mAh g-1 at 5 C), and an ultralow decaying rate of 0.047% per cycle after 800 cycles at 1 C. Even employed with a high sulfur loading of 7.08 mg cm-2 under lean electrolyte, an ultrahigh areal capacity of 4.5 mAh cm-2 is acquired, demonstrating a future practical application.

Constructing robust heterostructured interface for anode-free zinc batteries with ultrahigh capacities

The development of Zn-free anodes to inhibit Zn dendrite formation and modulate high-capacity Zn batteries is highly applauded yet very challenging. Here, we design a robust two-dimensional antimony/antimony-zinc alloy heterostructured interface to regulate Zn plating. Benefiting from the stronger adsorption and homogeneous electric field distribution of the Sb/Sb2Zn3-heterostructured interface in Zn plating, the Zn anode enables an ultrahigh areal capacity of 200 mAh cm−2 with an overpotential of 112 mV and a Coulombic efficiency of 98.5%. An anode-free Zn-Br2 battery using the Sb/Sb2Zn3-heterostructured interface@Cu anode shows an attractive energy density of 274 Wh kg−1 with a practical pouch cell energy density of 62 Wh kg−1. The scaled-up Zn-Br2 battery in a capacity of 500 mAh exhibits over 400 stable cycles. Further, the Zn-Br2 battery module in an energy of 9 Wh (6 V, 1.5 Ah) is integrated with a photovoltaic panel to demonstrate the practical renewable energy storage capabilities. Our superior anode-free Zn batteries enabled by the heterostructured interface enlighten an arena towards large-scale energy storage applications.

3D printing flexible zinc-ion microbatteries with ultrahigh areal capacity and energy density for wearable electronics.

A flexible zinc ion micro-battery with ultra-high surface capacity (10.1 mA h cm-2) and energy density (8.1 mW h cm-2), as well as good flexibility, is fabricated based on the co-doping effect of V2O5 through an improved 3D printing technology, and is further integrated with flexible solar cells for self-powered wearable electronics.

Rational design of PANI‐modified three‐dimensional dendritic hierarchical porous Cu–Sn nanocomposites as thick anodes with ultrahigh areal capacity and good cycling stability

AbstractA simple and effective one‐step strategy gives freestanding 3D dendritic hierarchical porous (DHP) Cu–Sn nanocomposites by chemically dealloying a designed Cu35Sn65 (at.%) alloy with dendritic segregation in a specific corrosive solution. A 3D DHP Cu–Sn modified by polyaniline (PANI) further makes the nanocomposites with improved conductivity and structural stability, which are typical of bimodal pore‐size distribution comprising a dendritic micron‐sized ligament‐channel structure with interconnected nanoporous channel walls. The as‐prepared 12 h dealloyed 3D DHP nanocomposites with ca. 200 μm in thickness can serve as binder‐free thick anodes for lithium‐ion batteries (LIBs) and exhibit enhanced Li storage performance with a ultrahigh first reversible capacity of 13.9 mAh cm−2 and an initial CE of 85.8%, good cycling stability with a capacity retention of 73.5% after 50 cycles, and superior rate capability with a reversible capacity of 11.95 mAh cm−2 after high‐rate cycling. These Sn‐based anodes can effectively alleviate the volume variation, enhance the loading of active materials, strengthen the stability of solid electrolyte interphase films, shorten the Li+ migration distance, and improve the electron conductivity. Additionally, the Sn content and areal capacity of the 3D DHP electrode can be tuned by changing the dealloying time of the initial alloy for 3D tin‐based thick anodes with adjustable capacities toward high‐performance LIBs.

Back Cover Image, Volume 2, Issue 1, January 2023

Battery EnergyVolume 2, Issue 1 12092 COVEROpen Access Back Cover Image, Volume 2, Issue 1, January 2023 First published: 18 January 2023 https://doi.org/10.1002/bte2.12092AboutPDF ToolsExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Graphical Abstract Back Cover: In article number BTE2.20220032, Wenbo Liu and co-workers develop a simple and effective strategy to achieve PANI-modified freestanding 3D dendritic hierarchical porous Cu-Sn nanocomposites, which shows ultrahigh areal capacity and good cycling stability as additive-free thick anodes for LIBs. The Sn content and areal capacity can be tuned easily by changing the dealloying time of initial alloy for 3D tin-based thick anodes with adjustable capacities toward high-performance LIBs. Volume2, Issue1January 202312092 RelatedInformation

Ultrahigh-capacity epitaxial deposition of planar Zn flakes enabled by amino-rich adhesive hydrogel electrolytes for durable low-temperature zinc batteries

Aqueous zinc batteries (AZBs) show promising applications in large-scale energy storage and wearable devices, but suffer from poor reversibility of Zn anodes due to zinc dendrites and possible side reactions. We prepared amino-enriched polypyrrole modified polyacrylamide hydrogel for using as electrolytes in AZBs. The proposed electrolyte exhibits excellent adhesiveness of 19.8 kPa at room temperature (RT), high Zn2+ ion conductivity of 17.6 mS cm−1 at -20 °C, superior elongation of over 1000%, and fast self-healing in ten seconds at -30 °C. The proposed electrolyte enables unique epitaxial Zn deposition with ultra-high areal capacity up to 100 mAh cm−2 under 2 mA cm−2 in symmetric zinc cells. Importantly, this electrolyte assembled quasi-solid-state Zn/V2O5 batteries deliver a high capacity of 200 mAh g−1 at 1 A g−1 and a high capacity retention of 96.4% after 2000 cycles at -20 °C, demonstrating the promising features of the hydrogel electrolytes in high-performance AZBs.

Direct Ink Writing of 3D Zn Structures as High‐Capacity Anodes for Rechargeable Alkaline Batteries

The relationship between structure and performance in alkaline Zn batteries is undeniable, where anode utilization, dendrite formation, shape change, and passivation issues are all addressable through anode morphology. While tailoring 3D hosts can improve the electrode performance, these practices are inherently limited by scaffolds that increase the mass or volume. Herein, a direct write strategy for producing template‐free metallic 3D Zn electrode architectures is discussed. Concentrated inks are customized to build designs with low electrical resistivity (5 × 10−4 Ω cm), submillimeter sizes (200 μm filaments), and high mechanical stability (Young's modulus of 0.1–0.5 GPa at relative densities of 0.28–0.46). A printed Zn lattice anode versus NiOOH cathode with an alkaline polymer gel electrolyte is then demonstrated. This Zn||NiOOH cell operates for over 650 cycles at high rates of 25 mA cm−2 with an average areal capacity of 11.89 mAh cm−2, a cumulative capacity of 7.8 Ah cm−2, and a volumetric capacity of 23.78 mAh cm−3. A thicker Zn anode achieves an ultrahigh areal capacity of 85.45 mAh cm−2 and a volumetric capacity of 81.45 mAh cm−3 without significant microstructural changes after 50 cycles.

Wide‐Temperature, Long‐Cycling, and High‐Loading Pyrite All‐Solid‐State Batteries Enabled by Argyrodite Thioarsenate Superionic Conductor

AbstractRechargeable FeS2 battery has been regarded as a promising energy storage device, due to its potentially high energy density and ultralow cost. However, the short lifespan associated with the shuttle effect of polysulfides, large volume change, agglomeration of Fe0 nanoparticles, narrow operating temperature range, and sluggish reaction kinetics, greatly impede the application of rechargeable FeS2 lithium‐ion batteries. Herein, an all‐solid‐state battery (ASSB) coupling commercialized FeS2 is proposed with a novel superionic conductor Li6.8Si0.8As0.2S5I (LASI‐80Si) to overcome these challenges. The shuttle effect of polysulfides and volume change of FeS2 are suppressed or completely eliminated in ASSB, due to solid‐solid conversion of Li2S/S and large stacking pressure, respectively. Furthermore, the operating temperature range (−60–60 °C) is significantly expanded by the ultra‐high and temperature‐insensitive ionic conductivity of LASI‐80Si (Ea = 0.20 eV), along with the superior FeS2/LASI‐80Si interface stability. Thanks to the extra Li+ provided by Li2S and LiI functional phases, the “bridge” effect of LiI on facile interfacial Li‐ion conduction, and the enhanced reaction kinetics of LASI‐80Si ( 10.4 mS cm−1), ASSBs with LASI‐80Si deliver long cycle life (244 cycles at 0.1 C and 600 cycles at 1 C), superior rate capability (20 C), high areal mass loading (13.37 mg cm−2), and ultrahigh areal capacity (9.05 mAh cm−2). These inspiring results demonstrate the enormous potential of LASI‐80Si and FeS2 combination for practical application of wide‐temperature and large‐capacity ASSBs.

Ultrahigh areal capacity silicon anodes realized via manipulating electrode structure

High areal capacity is critical towards the practical application of silicon anodes for high-energy lithium ion batteries. Herein, a free-standing silicon-graphene (3D-Si/G) anode with ultrahigh areal capacity is proposed by manipulating electrode structure using 3D-printing. For the 3D-Si/G electrodes with the circle-grid pattern, electrode thickness and printed filament spacing can be precisely constructed and adjusted by controlling a computer program. In this configuration, the tailored free space between and inside the filaments are enough to withstand volume fluctuation of silicon anodes, which significantly improves the structure stability and integrity of electrodes and endows the great accessibility to lithium ions transport in thick electrodes. Furthermore, the unique edge-coaxial and internal-disordered structure in printed filaments greatly enhances the electrode mechanical stability. Simultaneously, the graphene framework with excellent electron-ion transport characteristic ensures fast electrochemical reaction kinetics and low electrochemical polarization in thick electrodes. Therefore, the optimized 3D-Si/G electrode achieves a favorable cycle stability with 8.5 mAh cm −2 after 70 cycles (capacity retention of 75.4%). And the 3D-Si/G thick electrode with four layers achieves a reversible ultrahigh areal capacity of 16.2 mAh cm −2 . More importantly, the easy ink preparation and controllable printing process provide broad prospects for the commercial application of silicon anodes.

Modulating Electron Conducting Properties at Lithium Anode Interfaces for Durable Lithium-Sulfur Batteries.

The lithium (Li) ion and electron diffusion behaviors across the actual solid electrolyte interphase (SEI) play a critical role in regulating the Li nucleation and growth and improving the performance of lithium-sulfur (Li-S) batteries. To date, a number of researchers have pursued an SEI with high Li-ion conductivity while ignoring the Li dendrite growth caused by electron tunneling in the SEI. Herein, an artificial anti-electron tunneling layer with enriched lithium fluoride (LiF) and sodium fluoride (NaF) nanocrystals is constructed using a facile solution-soaking method. As evidenced theoretically and experimentally, the LiF/NaF artificial SEI exhibits an outstanding electron-blocking capability that can reduce electron tunneling, resulting in dendrite-free and dense Li deposition beneath the SEI, even with an ultrahigh areal capacity. In addition, the artificial anti-electron tunneling layer exhibits improved ionic conductivity and mechanical strength, compared to those of routine SEI. The symmetric cells with protected Li electrodes achieve a stable cycling of 1500 h. The LiF/NaF artificial SEI endows the Li-S full cells with long-term cyclability under conditions of high sulfur loading, lean electrolyte, and limited Li excess. This study provides a perspective on the design of the SEI for highly safe and practical Li-S batteries.