Cathode Applications Research Articles

The engineering strategy in fabrication and application of high-specific-energy cathode for thermal battery

Nickel chloride is a promising material as cathode candidate for thermal battery, attributed to its superior electrochemical performance including high operating voltage and high specific energy. However, high polarization and structural collapse have emerged as major challenge hindering the practical application of NiCl2 cathode. Herein we propose an engineering strategy to construct a high-specific-energy NiCl2-based cathode with rhombohedral structure and amorphous carbon-layer skin structure. Benefited from delicate structural characteristic and improved electrochemical activity, the cathode designed remarkably elevates the plateau voltage of a single cell to 2.5 V and achieves, for the first time, a specific energy of 266.5 Wh/kg at current density of 600 mA/cm2 in the thermal battery tests. Notably, in contrast to the lab-level methods, this engineering strategy is an industrially feasible approach to manufacture NiCl2-based cathode for expanded application in thermal battery. This strategy also provides new insight into the design of high-performance cathode.

Effect of Conductive Coating on Silver/Silver Chloride Electrodes for Cathodic Protection Application

Measurement of pipe to soil potential in a cathodic protection system is something that must be done which aims to monitor the performance of the installed cathodic protection system. The main measuring tool in measuring pipe to soil potential is the reference electrode. The stability of the reference electrode is important as a validation of the measurement results. So far, the stability of the reference electrode is very difficult to maintain due to frequent changes caused by the environment, especially for permanent reference electrodes that are buried in the underground or installed in seawater. Permanent reference electrode sensors commonly used in seawater is the Ag/AgCl reference electrode, but in fact the Ag/AgCl reference electrode is generally unstable and must be stabilized with a KCl solution and other problems have not been produced in Indonesia. This research will be carried out by adding a conductive layer to the Ag/AgCl electrode so that its stability can be increased. The sensor manufacturing process starts from pretreatment, electrolysis and product characterization. The results of the best coating thickness and weight gain experiments showed by the highest voltage variations and time variations (4000mV and 60 minutes). The presence of conductive solid material increases corrosion resistance from 0.00391 mm/year to 0.19549 mm/year and increases the stability of the Ag/AgCl layer ± 5 mV.

Redox-Active Covalent Organic Framework with Highly Accessible Aniline-Fused Quinonoid Units Affords Efficient Proton Charge Storage.

Owing to their intrinsic safety and sustainability, aqueous proton batteries have emerged as promising energy devices. Nevertheless, the corrosion or dissolution of electrode materials in AICDic electrolytes must be addressed before practical applications. In this study, we developed a cathode material based on a redox-active 2D covalent organic framework (TPAD-COF) featuring inherently regular open porous channels and excellent stability. Benefiting from its superhydrophilicity, intrinsic high proton conductivity, excellent redox reversibility of enriched aniline-fused-quinonoid units, and the insolubility of the rigid framework skeleton, TPAD-COF cathode delivers a high capacity of 126 mAh g-1 at 0.2 A g-1 , paired with long-term cycling stability with capacity retention of 84% after 5,000 cycles at 2 A g-1 . Comprehensive ex-situ spectroscopic studies correlated with density functional theory (DFT) calculations revealed that both the -NH- and C = O groups of the aniline-fused quinonoid units exhibited prominent redox activity of six electrons during the charge/discharge processes. Furthermore, the assembled punch battery consisting of a TPAD-COF//anthraquinone (AQ) all-organic system delivers a discharge capacity of 115 mAh g-1 at 0.5 A g-1 after 130 cycles, implying the potential applications of TPAD-COF cathode in aqueous proton batteries. This study provides a new perspective on the design of electrode materials for aqueous proton batteries with long-term cycling performance and high capacity. This article is protected by copyright. All rights reserved.

Enhanced electron cloud through π-π interaction in charge-transfer complexes for all-solid-state lithium batteries

Organic cathodes have the advantages of abundant resources, high theoretical specific capacity, and mild synthesis conditions, but suffer from low density, poor electronic conductivity, and high solubility in liquid electrolytes. Herein, we develop a charge-transfer complex by combining 2,5-dihydroxyterephthalic acid (Li4C8H2O6) and tetracyanoquinodimethane (TCNQ) at room temperature in 1,3-Dioxolane (DOL) solvent, for application in all-solid-state battery to overcome the above problems. Li4C8H2O6 /TCNQ act as the electron donor/acceptor and combine to form an enhanced electron cloud through π-π interaction to facilitate electron transport. The electron conductivity of charge transfer complex Li4C8H2O6-TCNQ is enhanced to 7 × 10−5 S/cm, which is three orders of magnitude higher than the two pristine materials and much higher than most conventional organic cathodes. The Li4C8H2O6-TCNQ electrode exhibits a discharge specific capacity of 172 mAh/g at 0.5 C, which is approximately 2.5 times higher than that of Li4C8H2O6 and higher than its capacity in a liquid cell, and is stable for 100 cycles at 2 C. This result demonstrates that enhancing electron cloud through π-π interaction in charge transfer complexes is an effective way to realize the practical application of organic cathodes in sulfide all-solid-state batteries.

Fabrication of Self-Rolled Fluorinated Graphene Nanosheets and Cathode Application

A simple approach of self-rolled fluorinated graphene nanosheets (srFGN) was reported in this work. Notably, the preparation of the specific srFGN showed interesting solvent-sensitive characteristics. The research findings revealed that when an aprotic solvent was used, e.g., dimethyl sulfoxide (DMSO), the interesting srFGN was obtained readily, which was characterized by different technologies. Cathode application for primary lithium-ion batteries (LIBs) of the prepared srFGN nanoscrolls was also studied in this work, which exhibited elevated energy density (e.g., 2287.9 Wh·kg−1), excellent discharge specific capacity and reliable discharge platform, indicating it a cheap and hyperdensity cathode material for primary LIBs.

Revealing the Subzero-Temperature Electrochemical Kinetics Behaviors in Ni-Rich Cathode.

The sluggish kinetics in Ni-rich cathodes at subzero temperatures causes decreased specific capacity and poor rate capability, resulting in slow and unstable charge storage. So far, the driving force of this phenomenon remains a mystery. Herein, with the help of in-situ X-ray diffraction and time of flight secondary ion mass spectrometry techniques, the continuous accumulation of both the cathode electrolyte interphase (CEI) film formation and the incomplete structure evolution during cycling under subzero temperature are proposed. It is presented that excessively uniform and thick CEI film generated at subzero temperatures would block the diffusion of Li+ -ions, resulting in incomplete phase evolution and clear charge potential delay. The incomplete phase evolution throughout the Li+ -ion intercalation/de-intercalation processes would further cause low depth of discharge and poor electrochemical reversibility with low initial Coulombic efficiency, as well. In addition, the formation of the thick and uniform CEI film would also consume Li+ -ions during the charging process. This discovery highlights the effects of the CEI film formation behavior and incomplete phase evolution in restricting electrochemical kinetics under subzero temperatures, which the authors believe would promote the further application of the Ni-rich cathodes.

Development of Electrolyte Additives to Enable High-Voltage LiNi0.5Mn1.5O4 Lithium Ion Batteries

Electrochemical energy storage (EES) is still key to realize wide spread use of renewable energies. For large-scale EES production, the development of high energy density, non-toxic, cost-effective materials is necessary. In this study, a cobalt free active material, Lithium Nickel Manganese Oxide, LiNi0.5Mn1.5O4 (LNMO), was employed in the production of cathodes for high voltage lithium ion battery (LIB) applications. LNMO is an attractive cathode active material due to its high operating potential (~4.7 vs. Li/Li+ [1]), non-toxicity and low cost. The practical application of LNMO cathodes in LIBs has been relatively limited, especially for large scale application, due challenges associated with the material (i.e. electrolyte decomposition at high voltage, self-discharge and dissolution of the transition metals [2]).Electrolyte additives are an effective way to address these challenges, without major cost increase or changes to the production approach. In this study the role of different electrolyte additives in high-voltage full-cell LIBs with both graphite and silicon-graphite anodes is investigated. Additives known for their solid electrolyte interphase (SEI) forming ability (i.e. vinylene carbonate (VC) and fluoroethylene carbonate (FEC)), as well as additives that play additional roles such as cathode electrolyte interface formation or HF scavenging (i.e. tris(trimethylsilyl) phosphite (TMSP) and succinate anhydride (SA)), are used [3]. Galvanostatic cycling measurements were performed in 3-electrode cells in order to investigate the rate capability and long term cycling stability of LMNO/Gr and LMNO/Gr-Si full-cells with different electrolyte additives. The electrochemical characterization was verified with post mortem analysis to confirm the SEI composition, chemical and mechanical stability of the electrodes and lack of lithium plating. Post mortem investigations were done with Raman spectroscopy, scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX) and optical microscopy. Improved rate performance and better long term cycling stability of both full-cell chemistries was achieved for electrolytes containing the TMSP additive.

Elucidating the Mechanisms of Oxygen Depolarized Cathode Catalyst Degradation

Fe-N-C has shown to be a viable low-cost, PGM-free catalyst to replace RhS/C for oxygen-depolarized cathode applications. Though it possesses high intrinsic ORR activity and relatively good immunity towards chloride ion poisoning, further studies must be conducted to explore the degradation pathways of Fe-N-C in a wide pH range to realize its capabilities in concentrated hydrochloric acid and Chlor-alkali electrolysis1.Moreover, Fe-N-C has been shown to maintain performance after being in operation for more than one hour with three uncontrolled shutdowns, nearly matching RhS/C at a current density of 0.5 A/cm2 with a cell potential of 1.38 V1. Thus, we will perform long-term durability tests under Raman and X-ray absorption spectroscopy (XAS). Furthermore, a single electrochemical flow cell will be designed for both spectrochemical methods to characterize the interaction between the catalyst and the formation of products during the uncontrolled shutdown. Specifically, Raman spectroscopy will be utilized to detect changes in the catalyst structure if any Fe-N4 bonds are broken or changed due to chloride anions upon shutdown. XAS-Fe edge will be employed to elucidate the formation of Fe-Cl bonds due to crossover anions during operation and when the cell is removed from the power supply. By determining the degradation pathways or lack of, we can truly assess the viability of Fe-N-C as a replacement for RhS/C in hydrochloric acid and Chlor-alkali electrolysis. These techniques provide a platform to reduce experimental uncertainty and gain further insight into the degradation of both catalyst and membrane-electrode assembly performance.

Constructing a robust Li-rich Mn-based oxide cathode with oxygen vacancies and strong B-O bonds by BN treatment

Li-rich Mn-based oxide cathodes are one of the most promising cathode candidates for high energy density over 400 Wh kg−1, deriving from oxygen redox of Li-O-Li configuration. However, the deep oxygen oxidation would lead to the formation of peroxides and superoxides (O2n−, 0 < n ≤ 2) and even oxygen (O2), accompanied by crystal phase transformation and structure collapse. Herein, an integrative strategy of simultaneously regulating the right amount of oxygen vacancies (OVs) and B-atom doping is proposed to achieve differentially modification of both R-3 m and C2/m phases. Firstly, Rietveld refinement, HRTEM and in situ XRD results reveal that the linear increase of OVs content is achieved by regulating the amount of BN and the selective introduction of OVs inside the C2/m phase makes the oxygen partial pressure lower in the weak O-Li-O bonds of TM-layer and inhibits oxygen release at over 4.5 V. Meanwhile, kinetics test shows oxygen defects would accelerate the Li+ diffusion and reduce the electronic impedance driven by uneven local charge distribution. Secondly, lattice analysis shows the strong covalent B-O bonds located at the tetrahedral site not only prevent the overoxidation of the oxygen atoms at high voltage, but also hinder the migration of Mn atoms through tetrahedral sites, which effectively avoids the damage of the crystal structure. As a result, the modified cathode exhibits the excellent discharge specific capacity of 272 mA h g−1 at 0.1C, higher rate performance of 145 mA h g−1 at 5C, an outstanding capacity retention rate of 93% at 1C and lower voltage decay value of 0.43 V after 200 cycles. This promising strategy could simultaneously achieve both high energy density and superior cycling stability and help to advance industrial application of Li-rich Mn-based Cathodes.

Construction of the hierarchical porous biochar with an ultrahigh specific surface area for application in high-performance lithium-ion capacitor cathode

Biochar with a highly accessible specific surface area can display a higher performance when it is used as the cathode of lithium-ion capacitors. Facing the complex composition and diversity of biomass precursors, there is a lack of a universally applicable method to construct hierarchical porous biochar controllably. In this work, a multi-stage activation strategy combining the feature of different activation methods is proposed for this target. To confirm the porous characteristic in prepared samples, N2 adsorption–desorption and transmission electron microscope were used. As the optimal sample, BC-P3K4S had the highest specific surface area of 3583.3 m2 g−1. Evaluated as the electrode for a lithium-ion capacitor, BC-P3K4S displayed a capacity of 139.1 mAh g−1 at 0.1 A g−1. After coupling it with pre-lithiated hard carbon, the full device exhibited a high energy density of 129.3 W h kg−1 at 153 W kg−1. The work outlined herein offers some insights into the preparation of hierarchical porous biochar from complex biomass by multistep activation method.Graphical

Reinterpreting the correlation between cycling stability of Ni-rich layered oxide cathode and the charging cut-off voltage in Li-ion batteries

Conventional view is that increasing the charging cut-off voltage will reduce the cycle life of LiNi0.8Co0.1Mn0.1O2 (NCM811) due to the intensification of electrode-electrolyte interface reaction, which strongly depends on the interface chemistry. However, we found the different trend when NCM811 is cycled in TLE electrolyte (ternary fluorinated lithium salts electrolyte). Specifically, the higher charging cut-off voltage applied, the better cycling stability obtained with 1000 cycles at 4.5 V/4.7 V, while 500 cycles at 4.3 V (capacity retention > 80 %). Herein, we revisit the correlation between cycling stability and charging cut-off voltage and have found that the cycling stability of NCM811 is more strongly related to interface chemistry. Charging at 4.5/4.7 V in TLE electrolyte, the content of inorganic components in cathode-electrolyte-interphase (CEI) and anode-electrolyte-interphase (AEI) are much higher than that obtained at 4.3 V due to the energy levels of the frontier molecular orbital of lithium salts, which is more resistant to oxidation and has higher mechanical strength to suppress the particle cracks. More importantly, the inorganic rich interface can prevent the crossover reaction between cathode and anode. This work clarifies the significance of interface chemistry to achieve high-voltage stability, and provides a valuable electrolyte formula for commercial application of high-performance Ni-rich layered oxide cathode at high-voltage.

Recent Advances and Perspectives on the Promising High-Voltage Cathode Material of Na3 (VO)2 (PO4 )2 F.

Na3 (VO)2 (PO4 )2 F (NVOPF) has emerged as one of the most promising cathode materials for sodium-ion batteries (SIBs) attributed to its high specific capacity (130 mAh g-1 ), high operation voltage (>3.9V vs Na+ /Na), and excellent structural stability (<2% volume change). However, the comparatively low intrinsic electronic conductivity (≈10-7 S cm-1 ) of NVOPF leads to unsatisfactory electrochemical performance, especially at high rates, limiting its practical applications. To improve the conductivity and enhance Na storage performance, many efforts have been devoted to designing NVOPF, including morphology optimization, hybridization with conductive materials, metal-ion doping, Na-site regulation, and F/O ratio adjustment. These attempts have shown some encouraging achievements and shed light on the practical application of NVOPF cathodes. This work aims to provide a general introduction, synthetic methods, and rational design of NVOPF to give a deeper understanding of the recent progress. Additionally, the unique microstructure of NVOPF and its relationship with Na storage properties are also described in detail. The current status, as well as the advances and limitations of such SIB cathode material, are reported. Finally, future perspectives and guidance for advancing high-performance NVOPF cathodes toward practical applications are presented.

A Mechanistic Insight into the Oxygen Redox of Li-Rich Layered Cathodes and their Related Electronic/Atomic Behaviors Upon Cycling.

Li-rich cathodes have been extensively investigated as their energy density is superior to Li stoichiometric cathode materials. In addition to the transition metal redox, this intriguing electrochemical performance originates from the redox reaction of the anionic sub-lattice. This new redox process, the so-called anionic redox or, more directly, oxygen redox in the case of oxides, almost doubles the energy density of Li-rich cathodes compared to conventional cathodes. Numerous theoretical and experimental investigations have thoroughly established the current understanding of the oxygen redox of Li-rich cathodes. However, different reports are occasionally contradictory, indicating that current knowledge remains incomplete. Moreover, several practical issues still hinder the real-world application of Li-rich cathodes. As these issues are related to phenomena resulting from the electronic to atomic evolution induced by unstable oxygen redox, a fundamental multiscale understanding is essential for solving the problem. In this review, we attempt to summarize the current mechanistic understanding of oxygen redox, the origin of the practical problems, and how current studies tackle the issues. This article is protected by copyright. All rights reserved.

A stable dual LiAlO2/Li2SiO3 coating LiNi0.8Co0.1Mn0.1O2 cathode towards ultra-long-life and wide-temperature lithium-ion battery

Ni-rich layered LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode material offers great potential for widespread applications due to its high capacity, non-toxicity, and low cost. However, the instability of the structure, large polarization and occurrence of side reactions during charge-discharge cycles greatly restrict the performance of LiNi0.8Co0.1Mn0.1O2. The stability of NCM811 can be improved through surface coating, but single-phase coating cannot achieve both high electronic conductivity and enhanced Li+ diffusion. Herein, LiAlO2 and Li2SiO3 are applied to prepare dual coating NCM811 (AS-NCM811) and build 3D Li+ diffusion channels and surface protection to improve both Li+ diffusion efficiency and electronic conductivity of NCM811. In addition, using LiAlO2 and Li2SiO3 in AS-NCM811 can enhance structural stability and reduce the likelihood of undesired side reactions occurring, which is verified by ex-situ X-ray diffraction and transmission electron microscopy. As a result, the AS-NCM811-based battery exhibits a remarkable cyclic ability and rate performance in widen temperature range (room temperature (RT) to 55 °C). AS-NCM811 shows an RT initial discharge capacity of 180.8 mAh g−1, while achieve a high-capacity retention of 92.6 % (100 cycles, 1C). Even at 55 °C, AS-NCM811 also retains 68.4 % of its capacity (143.5 mAh g−1) after 200 cycles under 1C. Overall, these findings pave a novel dual-coating way for the application of Ni-rich layered cathodes in high energy-density lithium-ions battery.

Effect of tungsten metal-oxide addition on physical, structural, and electrical properties of borophosphate glasses

Demand for electrical energy storage (EES) is growing, necessitating the development of improved batteries. Inorganic glassy materials are a class of essential electrodes due of their excellent conductivity and stable structures, they are appropriate for both cathode and anode applications. The most important characteristics that determine the dynamic behavior and rate performance of batteries are the ionic and electronic conductivities of active materials. In this sense, many crystalline, vitreous, and glass ceramics are investigated for their electrical properties. To create uniformly mixed glasses within the xLi2WO4–(50–x)Li2O–40P2O5–10B2O3 system, the melt-quenching technique is employed. Glasses containing up to 50 mol% Li2WO4 are synthesized with a substantial region of glass formation. They are homogeneous, transparent, and bubble-free. The structural approach and selected physical parameters of these glasses, such as density, molar volume, electrical conductivity, and glass transition temperature, are evaluated. The study emphasizes that an increase in the Li2WO4 amount leads to an elevation in both the density (ρ) and molar volume (Vm). Infrared spectroscopy identifies the presence of numerous structural units within the glass framework. Electrical conductivity measurements of the glasses are investigated using impedance spectroscopy. The measurements are taken over a wide frequency range of 10 Hz to 1 MHz and across temperatures ranging from 303K to 403K. It is highlighted that the electric conductivity rises as the Li2WO4 content is added. The glass with x = 30 mol% exhibits a dc conductivity of 8.63 × 10−7 (Ω−1 cm−1) at room temperature and 8.90 × 10−5 (Ω−1 cm−1) at 150°C. To gain insight into the conductivity relaxation mechanism, the frequency dependence of the glasses' conductivity is investigated. The results indicate that the ion transport in the glasses is governed by the correlated barrier hopping mechanism, which follows Jonscher's power behavior. The scaling conductivity spectra reveal that the conduction mechanism in the glasses is influenced by both temperature and composition.

Structural, electrical and electron emission property studies of high dielectric constant (Pb0.88La0.12)(Zr0.65Ti0.35)O3 ceramics for ferroelectric cathode applications

Ferroelectric materials with high dielectric constant produce high electron emission and the life span of ferroelectric cathodes might be potentially increased if their piezoelectric charge coefficient can be made negligible. For achieving these properties, two different methods were employed to synthesize (Pb0.88La0.12)(Zr0.65Ti0.35)O3 (PLZT12/65/35) ceramics viz., the conventional method (mortar and pestle) followed by uniaxial pressing and the high energy, mechanical activation method (abbreviated to MA, hereinafter). This was done using a high-energy ball mill to reduce particle size drastically. Cold isostatic pressing was used to compact the milled powder which resulted in a significant increase in the density. X-ray diffraction confirmed single phase with cubic perovskite structure. Particle size was measured from TEM images. Morphological studies were carried out by SEM analyses to observe the grain structure. Of these two syntheses methods, PLZT 12/65/35 ceramics prepared via high energy ball milling exhibited significantly higher dielectric constant, surpassing the previously reported values and also exhibited low remnant polarization value, negligible piezoelectric charge coefficient at room temperature. High temperature dielectric measurements at various frequencies confirm the relaxor behavior of PLZT 12/65/35 ceramics. Ferroelectric cathode configuration based on PLZT 12/65/35 ceramics with high relative permittivity allowed us to achieve exceptionally high current density and power obtained in Radio frequency range.

W doping improves the electrochemical performance of LiNi0.94Co0.04Al0.02O2 cathode through dual enhanced electronic and ionic conductivities: A study from DFT calculations and experimental results

The nickel content in LiNixCoyAl1-x-yO2 cathode material has been gradually increased for higher energy density. However, the rapid capacity degradation and poor rate capability hinder the application of Ni rich cathode. In this work, it tries to explore a strategy that W substituting can improve the electrochemical performance of LiNi0.94Co0.04Al0.02O2 (N94CA) cathode by modulating electronic and cationic conductivity. DFT calculations imply that the bandgap of the cathode material is reduced due to the increased number of electrons near the Fermi level. Such improved electronic conductivity subsequently leads to a promoted cyclability with a capacity retention of 92.92%. Furthermore, the doping of W6+ cations also reduces the energy barrier for the migration of Li+cations so that rate performance is greatly improved. The W doped LiNi0.94-xWxCo0.04Al0.02O2 (W-N94CA) cathode displays a specific capacity of 154.5 mAh·g−1 even at 5C rate, indicating high potential for future application.

One-Step β-Li2SnO3 Coating on High-nickel Layered Oxides &amp;lt;italic&amp;gt;via&amp;lt;/italic&amp;gt; Thermal Phase Segregation for Li-ion Batteries

The global energy storage markets have gravitated to high-energy-density and low cost of lithium-ion batteries (LIBs) as the predominant system for energy storage such as electric vehicles (EVs). High-Ni layered oxides are considered promising next-generation cathode materials for LIBs owing to their significant advantages in terms of high energy density. However, the practical application of high-Ni cathodes remains challenging, because of their structural and surface instability. Although extensive studies have been conducted to mitigate these inherent instabilities, a two-step process involving the synthesis of the cathode and a dry/wet coating is essential. This study evaluates a one-step β-Li2SnO3 layer coating on the surface of LiNi0.8Co0.2O2 (NC82) via the thermal segregation of Sn owing to the solubility limit with respect to the synthesis temperature. The doping, segregation, and phase transition of Sn were systematically revealed by structural analyses. Moreover, surface-engineered 5 mol% Sn-coated LiNi0.8Co0.2O2 (NC82_Sn5%) exhibited superior capacity retention compared to bare NC82 owing to the stable surface coating layer. Thus, the developed one-step coating method is suitable for improving the properties of high-Ni layered oxide cathode materials for application in LIBs.

Tailoring the growth of iron hexacyanoferrates for high-performance cathode of sodium-ion batteries

Iron hexacyanoferrate (FeHCF) is regarded as a promising cathode material of sodium-ion batteries (SIBs) due to the merits of easy preparation, low cost and three-dimensional open framework. However, the practical application of FeHCF is highly restricted by the intrinsic [Fe(CN)6]4- vacancy and coordinated water as well as nanoscale particles. Herein, sodium citrate is introduced to mediate the drawbacks of FeHCF, resulting in microscale particles with less water content. Accordingly, the modified sample, FeHCF-3, achieved the performance of 92 mA h g−1 at 100 mA g−1 and 80 % capacity retention after 300 cycles. Furthermore, an optimal iron hexacyanoferrate (FeHCF-H-2) with high-salt-concentration preparation is designed and performs a good reversibility of 96 mA h g−1 after 700 cycles at 100 mA g−1. Such strategy may drive the application of high-tap, low-defect and stable cathode for SIBs.

In-Situ-Polymerized 1,3-Dioxolane Solid-State Electrolyte with Space-Confined Plasticizers for High-Voltage and Robust Li/LiCoO2 Batteries.

In-situ-polymerized solid-state electrolytes can significantly improve the interfacial compatibility of Li metal batteries. Typically, in-situ-polymerized 1,3-dioxolane electrolyte (PDOL) exhibits good compatibility with Li metal. However, it still suffers from the narrow electrochemical window (4.1 V), limiting the application of high-voltage cathodes. Herein, a novel modified PDOL (PDOL-F/S) electrolyte with an expanded electrochemical window of 4.43 V and a considerable ionic conductivity of 1.95 × 10-4 S cm-1 is developed by introducing high-voltage stable plasticizers (fluoroethylene carbonate and succinonitrile) to its polymer network. The space-confined plasticizers are beneficial to construct a high-quality cathode-electrolyte interphase, hindering the decomposition of lithium salts and polymers in electrolytes at high voltage. The as-assembled Li|PDOL-F/S|LiCoO2 battery delivers superior cycling stability (capacity retention of 80% after 400 cycles) at 4.3 V, superior to that of pristine PDOL (3% after 120 cycles). This work provides new insights into the design and application of high-voltage solid-state lithium metal batteries by in situ polymerization.