Impressive Capacity Retention Research Articles

In Situ Gel Polymer Electrolyte with Rapid Li+ Transport Channels and Anchored Anion Sites for High‐Current‐Density Lithium‐Ion Batteries

AbstractIn situ formed gel polymer electrolytes (GPEs) have advantages in safety and adaptability to current high‐voltage lithium‐ion batteries (LIBs). However, it is challenging for GPEs to achieve stable cycling at high current densities. A flexible framework is proposed for stable in situ GPE, by introducing ─CF3 groups to the polymer network to establish rapid Li+ transport channels, and incorporating secondary amine N─H groups to anchor anion. The obtained GPE exhibits a high ionic conductivity of 2.6 mS cm−1 and a high Li+ transference number of 0.67. The assembled Li||NCM811 cell demonstrates excellent rate performance, with a discharging capacity of 112.3 mAh g⁻¹ at 10C, and capacity retention of 87.6% after 260 cycles at 1C. Furthermore, the assembled graphite||NCM811 cell demonstrates excellent long‐term cycling stability with impressive capacity retention of 73.2% after 300 cycles 3C (1.8 mA cm−2). This work presents a promising approach to enhancing the cycling stability of GPEs for high‐voltage LIBs at high current density.

MXene Surface Engineering Enabling High‐Performance Solid‐State Lithium Metal Batteries

AbstractSolid polymer electrolytes (SPEs) offer inherent advantages for battery applications, such as high safety and excellent processability, but their practical use is limited by challenges like low ionic conductivity, subpar mechanical properties, and instability of the electrode/electrolyte interface. Here, novel SPEs are developed by embedding 2D MXenes decorated at the surface with methoxypolyethylene glycol chains into poly(vinylidene fluoride)‐hexafluoropropylene matrices, enhanced with succinonitrile as a plasticizer. This innovative design improves the compatibility of the modified MXene in poly(vinylidene fluoride)‐hexafluoropropylene and, together with the synergistic effects of succinonitrile, promotes the dissociation of lithium salt. The SPE achieves ionic conductivity of 1.49 × 10−4 S cm−1 at 30 °C, and a Li‐ion transference number of 0.59. These results are supported by comprehensive experimental characterization, COMSOL simulations, and DFT calculations. This SPE enables stable and reversible Li plating/stripping for over 2100 h in Li/Li symmetric cells, while fabricated Li/LiFePO4 full cells deliver a notable capacity of 135.4 mAh g−1 with an average Coulombic efficiency of 98.9% after 100 cycles at 0.2 C. Furthermore, the Li/LiNi0.6Co0.2Mn0.2O2 full cells also demonstrate a capacity of 140.5 mAh g−1 after over 200 cycles at 0.5 C, showcasing an impressive capacity retention rate of 99.6%.

Rational design of alginate-derived network binder for high-performance silicon-based anodes in Li-ion batteries

This study developed a novel alginate-derived network binder, SAH, to enhance the performance and stability of silicon-based anodes in lithium-ion batteries. Integrating acrylic acid and 2-hydroxyethyl acrylate with sodium alginate through a one-pot polymerization and in-situ cross-linking method, SAH effectively addresses the volumetric expansion challenges associated with silicon anodes. This innovative binder maintains the structural integrity of the silicon anode through its rigid acrylic acid component, while the flexible acrylic-2-hydroxyethyl ester serves as a dynamic buffer to enhance flexibility. Sodium alginate contributes its intrinsic beneficial properties and imparts a robust three-dimensional network structure through effective coupling, allowing the binder to accommodate silicon volume changes during battery operation. Consequently, lithium-ion batteries incorporating this binder exhibited improved stability and extended cycle life, achieving an impressive capacity retention rate of 87.3 % after 100 cycles at 0.5C. This study highlights the potential of biopolymeric materials in enhancing the functionality of silicon-based anodes, contributing to the ongoing development of high-performance energy storage technologies.

Ultrafast Lattice Engineering for High Energy Density and High-Rate Sodium-Ion Layered Oxide Cathodes

Sodium-ion batteries attract significant interest for large-scale energy storage owing to abundant sodium reserves, while challenges remain in the high synthesis energy consumption, long synthesis period, and poor electrochemical performance of sodium-ion layered oxide materials. This study presents a general high-temperature thermal shock (HTS) strategy to synthesize and optimize sodium-ion layered oxides. The rapid ramping, sintering, and cooling processes minimize volatile sodium loss during HTS, facilitating the improvement of phase purity and effectively optimizing the microstructure of materials in a non-equilibrium state. As a proof of concept, Mn-based Na0.67MnO2 treated with HTS (NMO-HTS) suppresses Mn ion vacancy within transition material layers, thereby increasing the redox centers and lowering the Mn 3d orbital energy level. Besides, the formation of transition metal layer stacking faults mitigates the structural transformation and Na+-vacancies ordering arrangement during cycling. Consequently, the energy density of the NMO-HTS increases by 21.5% to 559 Wh kg-1, with an outstanding rate capability of 108 mAh g-1 at 10C and an impressive capacity retention of 93.7% after 300 cycles at 1C. In addition, we demonstrate the universality of HTS in synthesizing various other sodium-ion layered oxides, including nickel-based and iron-based cathodes, as well as in activating degraded materials.

Multifunctional carbonyl-rich compounds for constructing “corrosion-resistant electrodes and electrolyte interface” in high-voltage sodium-metal batteries

In recent years, there has been notable advancement in the development of high-performance materials for sodium-ion batteries, particularly in layered oxide cathodes. However, research on enhancing the interface between electrolytes and cathodes remains nascent. One promising approach involves the addition of electrolyte additives, recognized for their cost-effectiveness and efficiency in bolstering the electrode/electrolyte interface to enhance material stability during high-voltage cycling. In this work, we investigate the use of glutaric anhydride (GA) as an electrolyte additive to improve the cycling stability of NaNi1/3F1/3M1/3O2/Na (NFM/Na) high-voltage sodium-metal batteries. Batteries using GA-containing electrolytes demonstrate impressive capacity retention: 80.51 % after 200 cycles at 4.0 V and 76.01 % after 150 cycles at 4.1 V. The research delves into the mechanistic insights behind GA’s effectiveness in enhancing cyclic stability. Theoretical calculations reveal that GA plays a crucial role in modifying the structure of the first solvation shells, promoting the formation of an elastic cathode-electrolyte interface (CEI) film enriched with OCO groups. This uniform and stable CEI film effectively preserves the material’s crystal structure and mitigates the dissolution of transition metals, thereby prolonging battery lifespan under demanding extremely cycling conditions.

Synthesis and characterization of MoS2-carbon based materials for enhanced energy storage applications

The article delves into the synthesis and characterization of MoS2-carbon-based materials, holding promise for applications in supercapacitors and ion batteries. The synthesis process entails the preparation of MoS2 and its carbon hybrids through exfoliation, hydrothermal treatment, and subsequent pyrolysis. Various analytical techniques were employed to comprehensively examine the structural, compositional, and morphological properties of the resulting materials. The article explores the electrochemical performance of these electrode materials in supercapacitors and ion batteries (LiB, SiB, KiB). Electrochemical measurements were conducted in aqueous electrolyte for supercapacitors and various aprotic electrolytes for ion batteries. Results highlight the impact of the synthesis process on electrochemical performance, emphasizing factors such as capacitance, rate capability, and charge/discharge cycle performance. Hydrothermally treated MoS2-carbon exhibited a specific capacitance of approximately 150 F g-1 in supercapacitors, attributed to its high surface area and efficient charge storage mechanisms. Additionally, for Li-ion battery materials without hydrothermal treatment showed impressive capacity retention of around 88% after 500 charge-discharge cycles, starting with an initial specific capacity of about 920 mAh/g. Long-term stability was demonstrated in both supercapacitors and lithium-ion batteries, with minimal capacitance degradation even after extensive charge-discharge cycles. This research underscores the potential of MoS2-based materials as effective energy storage solutions.

CVD-Synthesized Titanium Carbide Nanoflowers as High-Performance Anodes for Sodium-Ion Batteries.

Sodium-ion batteries (SIBs) have emerged as promising candidates for energy storage applications due to the abundance and low cost of sodium. However, the larger radius of sodium ions limits their diffusion kinetics within electrode materials and contributes to electrode volume expansion. Here, we successfully synthesized porous titanium carbide (TiC) nanoflowers through chemical vapor deposition (CVD). The TiC nanoflowers exhibit exceptional electrochemical performance as SIB anodes, with their porous structure enhancing the conductivity, mechanical stability, and Na-ion diffusion. The TiC nanoflowers demonstrate a high reversible specific capacity of 73.5 mAh g-1 at 1 A g-1 after 2500 cycles, corresponding to an impressive capacity retention of 80.81%. Additionally, we developed a full sodium-ion cell utilizing TiC nanoflowers as the anode and Na3V2(PO4)3 as the cathode, which demonstrates a substantial reversible capacity and outstanding cycling stability. Our work presents a promising strategy for synthesizing nanostructured TiC materials as anode electrodes for SIBs.

In Situ Formation of Stable Dual-Layer Solid Electrolyte Interphase for Enhanced Stability and Cycle Life in All-Solid-State Lithium Metal Batteries.

All-solid-state lithium metal batteries have emerged as a promising solution to overcoming the energy density and safety challenges associated with conventional lithium-ion batteries. Solid polymer electrolytes, particularly those based on poly(vinylidene fluoride) (PVDF) and dimethylformamide (DMF), demonstrate significant potential. However, interfacial side reactions between residual DMF solvents and lithium metal present substantial challenges. In this study, we investigate the in situ formation of solid electrolyte interphase protective layers to mitigate these side reactions. By incorporating F-rich additives, such as fluoroethylene carbonate and lithium difluorophosphate, we successfully establish a dual-layer inorganic SEI structure characterized by an outer LiF layer and an inner Li2O layer. Consequently, our approach extends the cycle life of lithium symmetric batteries to 3000 h. Additionally, the Li||LiFePO4 solid-state battery demonstrates exceptional stability, enduring 400 cycles at a 1C rate with an impressive capacity retention of 84%. This strategic methodology effectively leverages the benefits of residual solvents, ensuring both enhanced battery efficiency and long-term operational stability for PVDF-based all-solid-state lithium metal batteries.

A Fast Self-Healing Binder for Highly Stable SiOx Anodes in Lithium-Ion Batteries.

Silicon oxide-based (SiOx-based) materials show great promise as anodes for high-energy lithium-ion batteries due to their high specific capacity. However, their practical application is hindered by the inevitable volumetric expansion during the lithiation/delithiation process. Constructing high-performance binders for SiOx-based anodes has been regarded as an efficient strategy to mitigate their volume expansion and preserve structural integrity. In this work, we propose a green water-solution PAA-LS binder composed of poly(acrylic acid) (PAA) and sodium lignosulfonate (LS) with fast self-healing properties. The designed binder can be restored due to the strong affinity between Fe3+-catechol coordination bonds, thereby effectively alleviating the volumetric strain of SiOx-based anodes. Notably, with an optimized LS content of 0.5%, the SiOx@PAA-LS electrode exhibits excellent performance, delivering a high capacity of 997.3 mAh g-1 after 450 cycles at 0.5 A g-1. Furthermore, the SiOx||NCM622 full cell also demonstrates superior cycling stability, maintaining a discharge capacity of 147.58 mAh g-1 after 100 cycles at 0.5 A g-1, with an impressive capacity retention rate of 82.72%.

High performance NiCoSe2@NiFe-MOF@AC Nanocomposite electrode for energy storage and precise detection of mono-sodium glutamate

Hybrid supercapacitors, a fascinating appliances that combines the best of both batteries and supercapacitors, showcase remarkable improvements in power and energy densities. Here, a two-step technique was used to synthesis NiCoSe2@NiFe-MOF. In first step NiCoS was synthesis using electrodeposition approach and in second step the NiCoSe2@NiFe-MOF was synthesis using vacuum-assisted filtering. The specific capacitance of the NiCoSe2@NiFe-MOF composite used as the supercapacitor electrode in a three-electrode system was (2882.5 F g−1) and specific capacity is 1729.8 C g−1, much greater than that of the NiCoSe2 electrode material which was 967.4 C g−1 at current density of 1.5 Ag−1, In addition, a hybrid supercapacitor device (NiCoSe2@NiFe-MOF//AC) has been developed and successfully demonstrates a specific capacity of 205.45 C g−1 at 0.5 A g−1. The energy density is measured in units of WhKg−1 with a numeric values of 78.3, while at 2.9 KWKg−1 the power density is recorded. This device has been tested for up to five thousands cycles of discharging (87.8%) and charging (94.2%), achieving an impressive capacity retention rate of 96.8%.Additionally, an amperometric immunosensor was fabricated by employing the NiCoSe2@NiFe-MOF nanocomposite to detect Mono-Sodium Glutamate (MSG). A constant linear association was observed between the concentration of MSG and the variation in current, encompassing the entire detection range of 0.05–200 μM. The findings of our study offer an exciting starting point for the development of energy storage systems with greater capacity.

Stable and reversible zinc metal anode with fluorinated graphite nanosheets surface coating

A highly stable zinc metal anode modified with a fluorinated graphite nanosheets (FGNSs) coating was designed. The porous structure of the coating layer effectively hinders lateral mass transfer of Zn ions and suppresses dendrite growth. Moreover, the high electronegativity exhibited by fluorine atoms creates an almost superhydrophobic solid−liquid interface, thereby reducing the interaction between solvent water and the zinc substrate. Consequently, this leads to a significant inhibition of hydrogen evolution corrosion and other side reactions. The modified anode demonstrates exceptional cycling stability, as symmetric cells exhibit sustained cycling for over 1400 h at a current density of 5 mA/cm2. Moreover, the full cells with NH4V4O10 cathode exhibit an impressive capacity retention rate of 92.2% after undergoing 1000 cycles.

Enhanced Hydrogen Bonding Through Strong Water‐Locking Additives for Long‐Term Cycling of Zinc Ion Batteries

AbstractThe promising energy storage devices, zinc ion batteries (ZIBs), face challenges such as dendritic growth and side reactions, which hinder their application and development. As a polar group, hydroxyl groups can utilize hydrogen bonding to stably anchor water molecules, preventing contact between water and the anode. Moreover, they can attract and guide Zn2+ to rapidly and uniformly deposit on the anode. Here, the introduction of multi‐hydroxyl water‐locking additive Lactobionic acid (LA) molecules is proposed into conventional electrolytes. Through an in situ reaction between the highly reactive carboxyl groups on LA molecules and the zinc anode, a stable multi‐hydroxyl protective layer is formed on the anode surface, effectively preventing interface corrosion and dendritic growth. As a result, the Zn||Zn symmetric cell with LA exhibits remarkable performance, cycling for 2300 h under 1 mA cm−2 and 1 mAh cm−2. Even under more rigorous conditions of 10 mA cm−2 and 10 mAh cm−2, it maintains over 800 h of cycling durability. Moreover, in the Zn||NH4V4O10 full cell configuration, an impressive capacity retention rate of 80.35% after 2000 cycles at a current density of 5 A g−1. This innovative method can open a new avenue for designing high‐performance ZIBs.

Investigation of Solid Polymer Electrolytes for NASICON-Type Solid-State Symmetric Sodium-Ion Battery.

The inevitable shift toward renewable energy and electrification necessitates earth-abundant sodium reserves for next-generation Na-based energy storage technologies. By coupling the benefits of solid electrolytes over traditional nonaqueous electrolytes due to their safety hazards, solid-state sodium-ion batteries hold huge prospects in the future. This work presents a comprehensively developed solid-state sodium-ion symmetric full cell operating at room temperature enabled through a poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP)-based polymer electrolyte and modified NASICON-structured positive and negative electrodes. Among the investigated polymer electrolytes, PVDF-HFP-NaTFSI was found to outperform other counterparts by achieving a higher ionic conductivity and delivered an appreciable electrochemical stability window. By further delving into the properties of PVDF-HFP-NaTFSI, it was found to possess the least crystallinity, minimal porous structure, lowest melting point, and fusion enthalpy, indicating better ion transport than other investigated polymer electrolytes. The as-assembled solid-state battery revealed a storage capacity of 74 mAh g-1 at 0.1 C with a specific energy density of 130 Wh kgcathode_active_material-1 and demonstrated an impressive capacity retention of 84% of the initial capacity after 200 cycles. The structure and morphology retention of the cycled electrode and electrolyte through postmortem analysis bolster the electrochemo-mechanical stability of the developed solid cell. The findings reported here on polymer electrolytes persuade expedient solutions for developing ambient temperature solid-state sodium-ion batteries with promising electrochemical performance for commercialization in the near future.

Weakening the Space Charge Layer Effect Through Tethered Anion Electrolyte and Piezoelectric Effect Toward Ultra-Stable Zinc Anode.

The space charge layer (SCL) dilemma, caused by mobile anion concentration gradient and the rapid consumption of cations, is the fundamental reason for the generation of zinc dendrites, especially under high-rate discharge conditions. To address the issue, a physical (PbTiO3)/chemical (AMPS-Zn) barrier is designed to construct stable zinc ion flow and disrupt the gradient of anion concentration by coupling the ferroelectric effect with tethered anion electrolyte. The ferroelectric materials PbTiO3 with extreme-high piezoelectric constant can spontaneously generate an internal electric field to accelerate the movement of zinc ions, and the polyanionic polymer AMPS-Zn can repel mobile anions and disrupt the anions concentration gradient by tethering anions. Through numerical simulations and analyses, it is discovered that a high Zn2+ transference number can effectively weaken the SCL, thus suppressing the occurrence of zinc dendrites and parasitic side reactions. Consequently, an asymmetric cell using the PbTiO3@Zn demonstrates a reversible plating/stripping performance for 2900h, and an asymmetric cell reaches a state-of-the-art runtime of 3450h with a high average Coulombic efficiency of 99.98%. Furthermore, the PbTiO3@Zn/I2 battery demonstrated an impressive capacity retention rate of 84.0% over 65000 cycles by employing a slender Zn anode.

Controllable In situ Polymerization of 1,3‐Dioxolane via Sustained‐Release Effect for Solid‐State Lithium Metal Batteries

AbstractIn situ formed poly(1,3‐dioxolane) (PDOL) electrolytes are of great interest due to the facile process and the improved interface contact. However, the practical application of in situ PDOL electrolytes is still plagued by fast solidification time (liquid state) and poor high‐voltage stability (solid state). Herein, the slow‐release carriers triglycidyl isocyanurate (TGIC), which play dual roles as initiator sustained‐release and network confinement, can tune DOL curing time and cathode/electrolyte interface chemistry is demonstrated. Specifically, the electronegative C≐O and epoxy groups in TGIC have an affinity with BF3, the decomposition product of lithium bis(oxalate)borate (LiDFOB), delaying BF3 protonation reaction and thus extending DOL solidification time. In addition, the epoxy groups in TGIC serve as crosslinking sites to form in situ crosslinked polymer electrolytes (TPDOL@FEC). The corresponding network structure suppresses the contact reaction between high‐fluidity organic components and cathodes, generating a uniform and thin cathode electrolyte interface layer. As a result, the TPDOL@FEC precursor solution can remain its liquid state even after resting 24 h at room temperature. The assembled LiNi0.6Co0.2Mn0.2O2||TPDOL@FEC||Li cells display an impressive capacity retention of 91.5% after 100 cycles at 4.4 V (0.5 C). This study is expected to be a leap in the pursuit of practically feasible in situ formed PDOL electrolytes.

One-step in situ doping of Sb achieves enhanced performance of [001]-oriented nano-LiFe0.6Mn0.4PO4/C cathode high-rate materials

The LiFe0.6Mn0.4PO4/C composite has become a cost-effective and reliable material for lithium battery storage in commercial applications, due to its significant safety benefits. However, its industrial application is limited by its suboptimal high-rate capacity and unsatisfactory cycling performance. To address this issue, Li(Fe0.6Mn0.4)1-xSbxPO4 (x = 0, 0.01, 0.03, 0.04, 0.05) materials were synthesized using a one-step solvothermal method in this study, aiming to modulate the microstructure and achieve Sb doping, thereby enhancing the electrochemical performance. The electrochemical test results indicate that LFMP/C doped with Sb (designated as LFMP/C-Sb0.04) displays exceptional electrochemical performance, with remarkable capacities of 166.6 mAh·g−1 and 146.8 mAh·g−1 at 0.2C and 1C, respectively. Notably, it achieves a capacity of 126.1 mAh·g−1 at a high rate (5C) and maintains an impressive capacity retention rate of 93.6 % after 300 cycles, outperforming the original LMFP/C (109.5 mAh·g−1), which retains only 61.5 % of its initial capacity. Further characterization of the samples reveals that in situ Sb doping promotes the growth of the [001] crystal orientation, enhancing the lithium-ion diffusion rate and effectively reducing electrode polarization and charge transfer resistance, thereby contributing to its exceptional rate performance. Moreover, Sb doping increases the M − O binding energy, strengthens the metal-oxygen framework, mitigates the Jahn-Teller effect caused by Mn3+ dissolution, and enhances its cycling stability.

High-performance single crystal Ni-rich cathode with regulated lattice and interface constructed by separated lithiation and crystallization calcination

Incorporating high valence dopants, such as W6+ and Mo6+ has been verified to be effective for tuning the microstructure and grain boundary of polycrystal Ni-rich cathode. However, the hindered consolidation of primary particles induced by dopants during lithiation calcination limits the utilization of those dopants to crystalize single-crystal Ni-rich cathodes with stabilized lattice and surface. Herein, high performance single crystal LiNi0.84Co0.11Mn0.05O2 cathode with Al3+ and W6+ regulated lattice and boundary phase was construed based on commercial process with two-step calcination process containing separated lithiation and crystallization. The introduction of appropriate amount of Al3+ in the first lithiation calcination of 6 h endows the bulk of crystalline with enhanced lattice stability, while the incorporation of W6+ with stoichiometrical LiOH in the secondary crystallization calcination of 6 h renders uniformly distributed surface layer without hampering the growth of single-crystal. With the Al3+ doped bulk lattice, W6+ doped subsurface region and hetero-epitaxially grown Li2WO4, the cathode infused by two-step calcination exhibits high discharge capacity, rate performance, and cycling stability. Specifically, the modified LiNi0.84Co0.11Mn0.05O2 exhibits exceptional capacity retention, maintaining 88.98% of its initial capacity after 200 cycles at a rate of 1 C within a voltage window of 2.7–4.3 V at a temperature of 25 °C in half-cell. This performance is markedly superior to the capacity retention of 72.96% observed for pristine cathode. Even when subjected to a stringent test after 200 cycles at the same rate, the modified cathode sustains an impressive capacity retention of 82.41% at an elevated cut-off voltage of 4.5 V and a temperature of 30 °C.

An alumina phase induced composite transition shuttle to stabilize carbon capture cycles

Limiting global warming to 1.5-2 °C requires a 50-90% reduction in CO2 emissions in 2050, depending on different scenarios, and carbon capture, utilization, and storage is a promising technology that can help reach this objective. Calcium oxide (CaO) carbon capture is an appealing choice because of its affordability, large potential capacity, and ability to withstand the high temperatures of flue gases. However, the structural instability and capacity fading challenge its large-scale industrial applications. Here, we design a reversible reaction shuttle in CaO-based sorbents to improve the structure stability by changing the initial alumina phases. Diverse alumina phases (x-Al2O3) are first synthesized and utilized as the aluminum source for creating CaO@x-Al2O3 composites. As expected, the CaO@δ-Al2O3 composite demonstrates a carbon capture capacity of 0.43 g-CO2/g-sorbent after 50 cycles, with an impressive capacity retention of 82.7%. Combined characterizations and calculations reveal that this stability improvement is attributed to a transition shuttle between Ca3Al2O6 and Ca5Al6O14, which can effectively restrain the complete decompositions of those structure-stabilized intermediate phases. An economic assessment further identifies the significance of heat transfer efficiency improvement upon cycles, and control of capital/operation cost, energy price and carbon tax for a future cost-effective commercialization of current strategy.

Surface to bulk design empowering Ni-rich layered oxide cathode in sulfide-based All-Solid-State batteries

All-solid-state batteries (ASSBs) employing sulfide solid electrolytes (SSE) and high-nickel layered oxide cathodes have attracted considerable attention, attributed to their superior safety and great potential for high energy densities. However, the interface compatibility between SSE and nickel-rich oxide cathode remains a challenge. Here, a dual-functional strategy of Li6.25La3Zr2Al0.25O12 surface coating and bulk Zr doping in LiNi0.8Co0.1Mn0.1O2 was proposed (NCM811@CD-LLZAO), aiming to enhance the interfacial compatibility toward sulfide-based ASSBs. The fabricated ASSBs exhibit an impressive capacity retention rate of 91.1% after 100cycles at 0.1C and can sustain an ultra-long cycling performance over 1000cycles at 1.0C. Remarkably, even at a high rate of 11.0C, the battery still maintains a high capacity, highlighting its excellent rate performance. The distribution of relaxation time (DRT) analysis reveals that the LLZAO buffering layer can enhance the kinetics at the cathode/electrolyte interface. Theoretical calculation further confirms that the strong Zr-O bond formed by Zr doping can stabilize the lattice oxygen and effectively prevent the sulfide solid electrolyte from further electrochemical oxidation, thereby enhancing the interfacial dynamic and stability. These encouraging results provide a new strategy for the practical application of high-energy–density ASSBs, enabling fast charge transfer, extended cycle longevity and enhanced safety.

Rational design of mangosteen-like bismuth nanospheres coated by N-doped carbon shell as superb composite anode for high-performance sodium-ion batteries

Metallic bismuth (Bi) anode materials are promising candidates for alkali-ion batteries due to its high theoretical gravimetric/volumetric capacity. However, the pronounced volume change from Bi to full sodiation phase Na3Bi, inducing the structural collapse, and ionic conduction interruption upon cycling, hinders their implementation in sodium-ion batteries (SIBs). Herein, a mangosteen-like bismuth nanosphere coated by N-doped carbon shell (Bi@NC) was designed and synthesized to address these limitations. Due to the nanosize of Bi core and in situ, generated N-doped carbon shell, this Bi@NC anode can not only effectively accommodate the volume change during the alloying/dealloying process but also provide high-speed channels for electron/ion transport to the highly active bismuth nanospheres. The Bi@NC electrode exhibits outstanding cycling stability (1000 cycles at 5 A g−1 with an impressive capacity retention of 96.5 %) and rapid sodium storage performance (392.8 mAh g−1 at 20 A g−1). Importantly, ex-situ techniques and kinetic analysis have revealed the distinctively sharp multiphase transitions and the “battery-capacitor dual-mode” sodium-storage mechanism. This research introduces a new approach to enhance the performance of bismuth-based anodes in advanced SIBs and demonstrates potential for practical applications.