Advanced Secondary Batteries Research Articles

Metal-organic framework-derived in situ-grown Cu2Sb@NC octahedra for high-performance stable lithium/sodium storage

Intermetallic compounds are considered a special class of alloy-type anode materials that show great potential for use in lithium/sodium-ion batteries due to their inherent advantages, such as high specific capacity and enhanced safety features. However, their practical application is often impeded by the substantial volume changes that occur during the insertion and extraction of Li+/Na+ ions, leading to capacity decay and reduced service life. To address this challenge, we developed a novel composite material comprising Cu2Sb nanoparticles encapsulated within a N-doped octahedral carbon matrix (Cu2Sb@N-C). This composite structure features a heteroatom-doped conductive network, a three-dimensional carbon framework, and finely dispersed Cu2Sb nanoparticles. Benefiting from the heteroatom-doped conductive network, three-dimensional carbon framework and ultrafine Cu2Sb nanoparticles, they not only provide a penetrating network for the fast transfer of charge carriers and improve the accessibility of ions, but also alleviate the agglomeration and volume expansion of Cu2Sb during cycling. For LIBs, the material exhibited a reversible capacity of 1001.0 mAh/g after 330 cycles at 0.2 A/g, while maintaining a substantial capacity of 565.5 mAh/g after 1000 cycles at 1.0 A/g. In the case of SIBs, the material exhibited a capacity of 375.6 mAh/g after 100 cycles at 0.2 A/g. Post-cycling electrode analyses revealed that the Cu2Sb@N-C anode material retained its structural integrity, demonstrating its ability to withstand the continuous insertion and extraction of Li+/Na+ ions. This research contributes insights into the effective design of innovative high-capacity alloy-based anode materials for advanced secondary batteries.

Na (100)‐Textured Electrode Embedded with Sb‐Doped SnO2 Nanoparticles for Dendrite‐Free Sodium Metal Batteries

AbstractSodium metal batteries (SMBs), the next‐generation advanced secondary batteries, have attracted extensive attention due to their low cost and high energy density. However, the unavoidable interfacial side reactions and uncontrollable dendrite growth severely restrict their practical application. In this work, a Na (100)‐textured composite anode embedded with antimony‐doped tin oxide (ATO) nanoparticles (ATO‐12Na) is innovatively designed via an accumulative roll bonding technique. It is observed that the Na (100) texture not only contributes to the formation of anion‐derived inorganic‐rich solid electrolyte interphase layer on the surface of ATO‐12Na composite anode but also efficiently induces the uniform and horizontal Na deposition during the pre‐deposition stage. Profiting from the intrinsic Na affinity of Na (100) texture and the high sodiophilicity of ATO active sites, the integrated composite anode exhibits enhanced interfacial compatibility and excellent Na plating/stripping stability. At 2 mA cm−2, the ATO‐12Na symmetric cell can operate steadily for more than 1400 h. The full cell assembled by ATO‐12Na anode and Na3V2(PO4)3 cathode delivers impressive long‐term cycling stability over 4500 cycles at 500 mA g−1 with a high capacity retention of 80.7%. This study offers a new approach to designing ultra‐stable, dendrite‐free, and high‐performance SMBs.

Chemical Doping and O-Functionalization of Carbon-Based Electrode to Improve Vanadium Redox Flow Batteries.

The vanadium redox flow battery (VRFB) holds promise for large-scale energy storage applications, despite its lower energy and power densities compared to advanced secondary batteries available today. Carbon materials are considered suitable catalyst electrodes for improving many aspects of the VRFB. However, pristine graphite structures in carbon materials are catalytically inert and require modification to activate their catalytic activity. Among the various strategies developed so far, O-functionalization and chemical doping of carbon materials are considered some of the most promising pathways to regulate their electronic structures. Building on the catalytic mechanisms involved in the VRFB, this concise review discusses recent advancements in the O-functionalization and chemical doping of carbon materials. Furthermore, it explores how these materials can be tailored and highlights future directions for developing more promising VRFBs to guide future research.

Binder design strategies for cathode materials in advanced secondary batteries

This review evaluates the binder design strategies for cathodes in advanced secondary batteries, offering clear guidance for the development of novel binders in terms of the failure behaviors of the cathode materials.

π-d conjugation regulates the cathode/electrolyte interface in all-solid-state lithium-ion batteries

π-d Conjugated coordination between the DHBQ electrode and LLTO-PVDF solid electrolyte stabilizes the contact interface.

Controllable amorphization and morphology engineering on mixed-valence MOFs for ultra-fast and high-stability near-pseudocapacitance Li+ storage.

Coulombic efficiency (CE) and rate capability are crucial parameters for advanced secondary batteries. Herein, for the first time, we report controllable amorphization and morphology engineering on mixed-valence Fe(II,III)-MOFs from the crystalline to amorphous state and micro-clustered to hollow nano-spherical geometry through valence manipulation by a dissolved oxygen-mediated pathway. The disordered structure and the hollow nanostructure can endow the MOFs with the highest initial CE (>80%) to date for MOF electrodes, and ultrafast and super-stable near-pseudocapacitance lithium storage. These findings can provide new ideas for the engineering of MOF systems for application in LIBs.

Engineering strategies of metal‐organic frameworks toward advanced batteries

AbstractMetal‐organic frameworks (MOFs) integrate several advantages such as adjustable pore sizes, large specific surface areas, controllable geometrical morphology, and feasible surface modification. Benefiting from these appealing merits, MOFs have recently been extensively explored in the field of advanced secondary batteries. However, a systematic summarization of the specific functional units that these materials can act as in batteries as well as their related design strategies to underline their functions has not been perceived to date. Motivated by this point, this review dedicates to the elucidation of diverse functions of MOFs for batteries, which involve the electrodes, separators, interface modifiers, and electrolytes. Particularly, the main engineering strategies based on the physical and chemical features to enable their enhanced performance have been highlighted for the individual functions. In addition, perspectives and possible research questions in the future development of these materials have also been outlined. This review captures such progress ranging from fundamental understanding and optimized protocols to multidirectional applications of MOF‐based materials in advanced secondary batteries.

Understanding the Advantageous Features of Bacterial Cellulose‐Based Separator in Li–S Battery

AbstractSeparator is a critical component of lithium–sulfur (Li–S) battery, and the property of separator influences the battery performance significantly. Cellulose‐based separator is emerging as a promising alternative to the traditional polyolefin separator used in Li–S battery. Although the excellent battery performance of various cellulose‐based separators is shown, a comprehensive understanding of the advantageous features of bacterial cellulose (BC)‐based separator in Li–S battery still is lacking. In this work, models of BC separators with different thicknesses are prepared and compared with polypropylene separators in terms of their electrochemical performance. The results show that the BC separator exhibits favorable electrolyte affinity, improved lithium‐ion transport, suppressed shuttling of soluble polysulfides, and inhibited the formation of lithium dendrites. The combination of these unique characters of BC separator endows it with excellent battery performance. These results provide insight into the use and design of functional cellulose‐based separators in advanced secondary batteries.

In Situ Multi-Modal Approach for Electrode-Electrolyte Interfacial Chemistryand Electrode and Electrolyte Aging Behavior Studies

Increasing demands for cost-effective electric vehicles and electrochemical energy storage systems require advanced secondary batteries with higher energy density, longer lifetime, and enhanced safety. Increase of the battery operating voltage is one realistic strategy to extend the energy density, but it is accompanied by irreversible structural changes to the electrodes and parasitic reactions within an electrode-electrolyte interphase resulting in capacity fading and subsequent battery failure. Therefore, a fundamental understanding of underlying electrochemical mechanisms in the electrodes during battery cycling is critical for the development of next-generation secondary batteries.Based on our previous studies utilizing in situ surface-enhanced Raman spectroscopy to monitor the evolution of the Si-electrolyte interphase1 and in situ ATR-FTIR to investigate the voltage dependent electrolyte solution structure changes at the interface, transition metal redox chemistry, and cathode/electrolyte interfacial layer evolution,2 recently we updated the in situATR-FTIR with a newly designed ‘full-cell’ that enables us to analyze the interfacial reactions and interactions on the surfaces of both electrodes that directly influence battery performance, lifetime, and safety. Specifically, we focus on transition metal complex formation and its effect on solid-electrolyte interphase (SEI) formation and evolution on the anode due to transition metal dissolution and crosstalk of Mn-rich cathodes at high voltages (≥4.4 V).In addition, using our multi-modal characterization—a combination of in situ gas chromatography with flame ionization detection (GC-FID) and in situ ATR-FTIR—(electro)chemical degradation of the electrolyte is correlated with gas evolution in the battery. For example, GC-FID measures increasing amounts of ethylene gas until the end the first charging cycle of a LiNiO2//Graphite cell with Gen2 electrolyte (LiPF6 in ethylene carbonate (EC):ethyl methyl carbonate (EMC), 3:7 wt.%). Concurrently, in situ ATR-FTIR shows decreasing concentration of EC solvent, as calculated from the FTIR intensity of EC vibrational absorption. Ethylene is a known by-product of ethylene carbonate electrochemical reduction and is produced during SEI formation.3 Quantifying multiphase reactions occurring during battery operation is critical to understanding and mitigating battery degradation pathways, and developing next-generation battery materials systems.

Zeolite Imidazolate Frameworks (ZIFs) Derived Nanomaterials and their Hybrids for Advanced Secondary Batteries and Electrocatalysis

Zeolite imidazolate frameworks (ZIFs), as a typical class of metal-organic frameworks (MOFs), have attracted a great deal of attention in the field of energy storage and conversation due to their chemical structure stability, facile synthesis and environmental friendliness. Among of ZIFs family, the zinc-based imidazolate framework (ZIF-8) and cobalt-based imidazolate framework (ZIF-67) have considered as promising ZIFs materials, which attributed to their tunable porosity, stable structure, and desirable electrical conductivity. To date, various ZIF-8 and ZIF67 derived materials, including carbon materials, metal oxides, sulfides, selenides, carbides and phosphides, have been successfully synthesized using ZIFs as templates and evaluated as promising electrode materials for secondary batteries and electrocatalysis. This review provides an effective guide for the comprehension of the performance optimization and application prospects of ZIFs derivatives, specifically focusing on the optimization of structure and their application in secondary batteries and electrocatalysis. In detail, we present recent advances in the improvement of electrochemical performance of ZIF-8, ZIF-67 and ZIF-8@ZIF-67 derived nanomaterials and their hybrids, including carbon materials, metal oxides, carbides, oxides, sulfides, selenides, and phosphides for high-performance secondary batteries and electrocatalysis.

Ultra-small few-layered MoSe2 nanosheets encapsulated in nitrogen-doped porous carbon nanofibers to create large heterointerfaces for enhanced potassium-ion storage

MoSe2 has recently attracted great interest in the development of high-performance potassium-ion batteries (PIBs) anode materials because of its high theoretical capacity. However, the practical application of MoSe2 in PIBs is still hampered by its low conductivity and large volumetric expansion upon cycling. In this work, ultra-small few-layered MoSe2 nanosheets are encapsulated in N-doped porous carbon nanofibers (N-PCNFs) by an electrospinning and in situ carbonization/selenization process to form MoSe2/N-PCNFs nanocomposites. The morphology of nanocrystalline MoSe2 is fine-tuned to maximize the heterointerfaces of dichalcogenide/carbon matrix that function as active sites for potassium-ion storage. Benefitting from the effective confinement of MoSe2 in the carbon matrix and the robust chemical bonds (CSe and CMo) formed at the heterointerfaces, the structure stability and charge transfer kinetics of MoSe2/N-PCNFs are significantly improved. Moreover, the one-dimensional structure of N-PCNFs accelerates ions/electrons-transfer kinetics. The optimized MoSe2/N-PCNF with a moderate MoSe2 content exhibits excellent electrochemical performance for PIBs. The electrochemical storage mechanism of MoSe2/N-PCNFs is investigated by in situ X-ray diffraction measurements. Density functional theory calculations verify the enhanced adsorption of potassium-ion and electron transport at the heterointerfaces. This work provides new insights into the design of MoSe2 based anodes for high-performance PIBs and other advanced secondary batteries.

Amorphization of germanium selenide driven by chemical interaction with carbon and realization of reversible conversion-alloying reaction for superior K-ion storage

Chemical interaction with carbon has been employed to establish electron conduction pathways through intimate contact with anode materials. It is highly plausible that the strong chemical interaction can change the crystallinity as well as bonding nature of anode materials. This highlights the importance of chemical interaction with carbon and its effects on the material and electrochemical properties of anode materials. However, this is not yet investigated. This study is the first report on the amorphization of layered structured GeSe induced by the chemical interaction and its implications on the electrochemical properties for K-ion batteries. The charge storage mechanism of GeSe/CNT composite, investigated using ex-situ X-ray diffraction, indicates that reversible conversion-alloying reaction of GeSe is realized by the amorphization, which is closely linked with weakening of Ge–Se bonds derived from the strong chemical interaction and a concomitant increase in K-ion diffusion. As a result, the GeSe/CNT composite exhibits excellent electrochemical properties. Similar amorphization driven by chemical interaction is also observed for other layered structured anode materials. This study provides new insights on the chemical interaction of layered anode materials with carbon. Our findings could effectively be used to realize reversible conversion reaction for other anode materials for advanced secondary batteries.

Metal-Organic Framework Derived Ultrafine Sb@Porous Carbon Octahedron via In Situ Substitution for High-Performance Sodium-Ion Batteries.

Alloying-type anode materials are regarded as promising alternatives beyond intercalation-type carbonaceous materials for sodium storage owing to the high specific capacities. The rapid capacity decay arising from the huge volume change during Na+-ion insertion/extraction, however, impedes the practical application. Herein, we report an ultrafine antimony embedded in a porous carbon nanocomposite (Sb@PC) synthesized via facile in situ substitution of the Cu nanoparticles in a metal-organic framework (MOF)-derived octahedron carbon framework for sodium storage. The Sb@PC composite displays an appropriate redox potential (0.5-0.8 V vs Na/Na+) and excellent specific capacities of 634.6, 474.5, and 451.9 mAh g-1 at 0.1, 0.2, and 0.5 A g-1 after 200, 500, and 250 cycles, respectively. Such superior sodium storage performance is primarily ascribed to the MOF-derived three-dimensional porous carbon framework and ultrafine Sb nanoparticles, which not only provides a penetrating network for rapid transfer of charge carriers but also alleviates the agglomeration and volume expansion of Sb during cycling. Ex situ X-ray diffraction and in situ Raman analysis clearly reveal a five-stage reaction mechanism during sodiation and desodiation and demonstrate the excellent reversibility of Sb@PC for sodium storage. Furthermore, post-mortem analysis reveals that the robust structural integrity of Sb@PC can withstand continuous Na+-ion insertion/extraction. This work may provide insight into the effective design of high-capacity alloying-type anode materials for advanced secondary batteries.

High-Mass-Loading Electrodes for Advanced Secondary Batteries and Supercapacitors

The growing demand for advanced electrochemical energy storage systems (EESSs) with high energy densities for electric vehicles and portable electronics is driving the electrode revolution, in which the development of high-mass-loading electrodes (HMLEs) is a promising route to improve the energy density of batteries packed in limited spaces through the optimal enlargement of active material loading ratios and reduction of inactive component ratios in overall cell devices. However, HMLEs face significant challenges including inferior charge kinetics, poor electrode structural stability, and complex and expensive production processes. Based on this, this review will provide a comprehensive summary of HMLEs, beginning with a basic presentation of factors influencing HMLE electrochemical properties, the understanding of which can guide optimal HMLE designs. Rational strategies to improve the electrochemical performance of HMLEs accompanied by corresponding advantages and bottlenecks are subsequently discussed in terms of various factors ranging from inactive component modification to active material design to structural engineering at the electrode scale. This review will also present the recent progress and approaches of HMLEs applied in various EESSs, including advanced secondary batteries (lithium-/sodium-/potassium-/aluminum-/calcium-ion batteries, lithium metal anodes, lithium-sulfur batteries, lithium-air batteries, zinc batteries, magnesium batteries) and supercapacitors. Finally, this review will examine the challenges and prospects of HMLE commercialization with a focus on thermal safety, performance evaluation, advanced characterization, and production cost assessment to guide future development.

Mechanical Integrity of Conductive Carbon-Black-Filled Aqueous Polymer Binder in Composite Electrode for Lithium-Ion Battery.

The mechanical stability of aqueous binder and conductive composites (BCC) is the basis of the long-term service of composite electrodes in advanced secondary batteries. To evaluate the stress evolution of BCC in composite electrodes during electrochemical operation, we established an electrochemical–mechanical model for multilayer spherical particles that consists of an active material and a solid-electrolyte-interface (SEI)-enclosed BCC. The lithium-diffusion-induced stress distribution was studied in detail by coupling the influence of SEI and the viscoelasticity of inorganic-filler-doped polymeric bonding material. It was found that tensile hoop stress plays a critical role in determining whether a composite electrode is damaged or not—and circumferential cracks may primarily initiate in BCC, rather than in other electrode components. Further, the peak tensile stress of BCC is at the interface with SEI and does not occur at full lithiation due to the relaxation nature of polymer composite. Moreover, mechanical damage would be greatly misled if neglecting the existence of SEI. Finally, the structure integrity of the binder and conductive system can be effectively improved by (1) increasing the carbon black content as much as possible in the context of meeting cell capacity requirements—it is greater than 27% and 50% for sodium alginate and the mixtures of carboxy styrene butadiene latex and sodium carboxymethyl cellulose, respectively, for composite graphite anode; (2) reducing the elastic modulus of SEI to less than that of BCC; (3) decreasing the lithiation rate.

Superior sodium-storage behavior of flexible anatase TiO2 promoted by oxygen vacancies

The miniaturization and rapid development of portable and wearable electronics require significant advances in new energy storage devices with high capacities and excellent mechanical properties. Along with flexible Li-ion batteries (LIBs), flexible Na-ion batteries (SIBs) are among the most promising power devices for portable and wearable electronics. Unfortunately, advances in the field of flexible SIBs have been relatively stagnant. In this work, we created a flexible anode for SIBs by applying a simple ex situ electrospinning method to introduce oxygen vacancies (Vo) into a TiO2 structure (F–TiO2-x). Thanks to the oxygen vacancies and inclusion of N-doped carbon nanofibers (CNFs), the F–TiO2-x electrode can deliver an ultrahigh reversible capacity of 353 mAh g−1 at 0.1C. Even at a relatively high current rate of 1C, a charge capacity of 331 mAh g−1 can still be obtained after 1000 cycles. Furthermore, a sodium-ion full cell with F–TiO2-x—Na2/3Ni1/3Mn2/3O2 full cell was assembled, delivering a high average voltage of 2.6 V (after 200 cycles, a reversible capacity of 158 mAh g−1 can be retained). Combining both experimental and first-principles density functional theory (DFT) methods, we show that the introduction of oxygen vacancies can alter the electronic structure and enhance the electronic conductivity of the electrode. Additionally, the wrapped N-doped CNFs can further enhance the sodium diffusion kinetics of sodium storage. Overall, the study of preparing an oxygen vacancy-containing flexible electrode is expected to offer new insights into fabricating high capacity flexible electrodes for advanced secondary batteries including SIBs.

The effects of anode additives towards suppressing dendrite growth and hydrogen gas evolution reaction in Zn-air secondary batteries

In our continual effort to develop a cost effective rechargeable Zn-air batteries, herewith, we demonstrated Zn anodes comprising of (i) 30 wt.% Zn: 3 wt.% bismuth oxide: 10 wt.% potassium sulfide (ZBK), (ii) 30 wt.% Zn: 3 wt.% bismuth oxide: 5 wt.% lead (II) oxide (ZBP), and (iii) 30 wt.% Zn: 3 wt.% bismuth oxide: 10 wt.% potassium sulfide: 5 wt.% lead (II) oxide additives (ZBKP) in 6 M KOH aqueous solutions and 1.88 wt.% polyacrylic acid as the gelling agent. KOH gel constituted the remaining mass of the anode wt.%. Results were confirmed via cycle voltammetry (CV), Tafel, electrochemical impedance spectroscopy (EIS), etc., measurements. Among the various Zn anodes analyzed, ZBKP showed a superior cathodic peak of − 1.805 and 1.950 V vs. Hg/HgCl at 5th and 40th cycles during electrochemical cycle voltammetry. Tafel fitting on linear polarization test shows that ZBK exhibits the highest corrosion behavior followed by ZBP while ZBKP has the lowest corrosion behavior with an estimated corrosion inhibition efficiency of 36.06%. Furthermore, ZBKP displays the lowest dendrite growth, least corrosion rate, and superior capacity even at 60th cycles compared to ZBK and ZBP. In view of our finding, ZBKP has a higher positive electrode potential compare to ZBK and ZBP electrodes. Thus, ZBKP is the most suitable for aqueous battery due to its low minimal side effect. Field emission-scanning electron microscopy/energy dispersive x-ray spectroscopy (FE-SEM/EDS) images confirm that the various elemental additives were evenly deposited on the Zn anode surface. Ex situ spectroscopy and electrochemical performance studies also verified that the dendrite-free nature of improved Zn anode and the modified interfaces between electrolyte and Zn play vital roles towards advancing the energy storage performance. With all this indices and yard stick, the level of improvement we demonstrated in this current study is attractive for the design of an advanced secondary zinc-air batteries.

Three-Dimensionally Porous Li-Ion and Li-S Battery Cathodes: A Mini Review for Preparation Methods and Energy-Storage Performance.

Among many types of batteries, Li-ion and Li-S batteries have been of great interest because of their high energy density, low self-discharge, and non-memory effect, among other aspects. Emerging applications require batteries with higher performance factors, such as capacity and cycling life, which have motivated many research efforts on constructing high-performance anode and cathode materials. Herein, recent research about cathode materials are particularly focused on. Low electron and ion conductivities and poor electrode stability remain great challenges. Three-dimensional (3D) porous nanostructures commonly exhibit unique properties, such as good Li+ ion diffusion, short electron transfer pathway, robust mechanical strength, and sufficient space for volume change accommodation during charge/discharge, which make them promising for high-performance cathodes in batteries. A comprehensive summary about some cutting-edge investigations of Li-ion and Li-S battery cathodes is presented. As demonstrative examples, LiCoO2, LiMn2O4, LiFePO4, V2O5, and LiNi1−x−yCoxMnyO2 in pristine and modified forms with a 3D porous structure for Li-ion batteries are introduced, with a particular focus on their preparation methods. Additionally, S loaded on 3D scaffolds for Li-S batteries is discussed. In addition, the main challenges and potential directions for next generation cathodes have been indicated, which would be beneficial to researchers and engineers developing high-performance electrodes for advanced secondary batteries.

Graphene Oxide Induced Surface Modification for Functional Separators in Lithium Secondary Batteries

Functional separators, which have additional functions apart from the ionic conduction and electronic insulation of conventional separators, are highly in demand to realize the development of advanced lithium ion secondary batteries with high safety, high power density, and so on. Their fabrication is simply performed by additional deposition of diverse functional materials on conventional separators. However, the hydrophobic wetting nature of conventional separators induces the polarity-dependent wetting feature of slurries. Thus, an eco-friendly coating process of water-based slurry that is highly polar is hard to realize, which restricts the use of various functional materials dispersible in the polar solvent. This paper presents a surface modification of conventional separators that uses a solution-based coating of graphene oxide with a hydrophilic group. The simple method enables the large-scale tuning of surface wetting properties by altering the morphology and the surface polarity of conventional separators, without significant degradation of lithium ion transport. On the surface modified separator, superior wetting properties are realized and a functional separator, applicable to lithium metal secondary batteries, is demonstrated as an example. We believe that this simple surface modification using graphene oxide contributes to successful fabrication of various functional separators that are suitable for advanced secondary batteries.

Carbon Nanofiber Elastically Confined Nanoflowers: A Highly Efficient Design for Molybdenum Disulfide-Based Flexible Anodes Toward Fast Sodium Storage.

Two-dimensional energy materials have been widely applied in advanced secondary batteries, among which molybdenum sulfide (MoS2) is attractive because of the potential for high capacity and good rate performance. The relatively low electronic conductivity and irreversible volume expansion of pure MoS2 still need to be improved. Here, a facile and highly efficient ex situ electrospinning technique is developed to design the carbon nanofiber elastically confined MoS2 nanoflowers flexible electrode. The flexible freestanding electrode exhibits enhanced electronic conductivities and ionic diffusion coefficients, leading to a remarkable high specific capacity (596 mA h g-1 at a current density of 50 mA g-1) and capacity retention (with 89% capacity retention after 1100 cycles at 1 A g-1). This novel idea underscores the potential importance of fabricating various flexible devices other than the sodium-ion battery.