Search

Developing biodegradable electrodes is a significant step toward environmental sustainability and cost reduction in battery technology. This paper presents a new approach that utilizes metal‐organic framework (MOF)‐encapsulated silicon nanoparticles (SiNPs) as the active anode material within a cellulose‐based electrode. The electrode is free‐standing, flexible, biodegradable, and significantly reduces the strain experienced by SiNPs during volume expansion, resulting in improved capacity and cycle life stability of SiNPs. The high porosity of the electrode creates efficient lithium (Li+) ion transport channels and enhances electrolyte absorption, thus promoting effective contact between the electrolyte and active material. The outcome is rapid electrode kinetics and a highly reversible discharge capacity of 1744.6 mAh g−1 at 0.5 A g−1 versus Li/Li+ over 1000 cycles. Further, full cell tests are conducted that demonstrate a stable cycle performance exceeding 3400 cycles, with an initial discharge capacity retention of 80.5% at 0.5 A g−1. By employing cellulose and avoiding toxic organic solvents and binders, the proposed approach is promising for a substantial reduction of the production costs of Li‐ion batteries. The scalability of the proposed method further enhances its practical viability, offering intriguing economic implications for the future of battery technology. [ABSTRACT FROM AUTHOR]

Calcium metal batteries, as one of the promising alternatives beyond Li‐metal technology, is held back by the lack of suitable cathodes of considerable energy storage capability, and Ca anodes of long‐term stability and lower polarization potentials for Ca‐plating/stripping. Here, by recycling cellulose waste paper, feasible cathodes for Ca‐metal batteries of good high‐voltage and wide‐window‐voltage adaptability (0.005–4.9 V versus Ca/Ca2+), and impressive energy density (≈517.5 Wh kg−1 at 0.1 A g−1) are developed. Meanwhile, through tailorable Ca‐plating/stripping potentials (∆V≈ 0.65 V) realized by a modified electrolyte of Li+, Ca2+, BF4−, and PF6− multi‐ions system, the proof‐of‐concept Ca‐metal batteries not only delivered enhanced storage capability (101 mAh g−1 versus 51 mAh g−1 at 0.1 A g−1 in the window voltage of 2.0–4.7 V) and cycling stability (≈77% capacity retention for 100 cycles), but also simultaneously show a high output average working voltage of ≈3.2 V. The work provides a hint that mixed metal deposition under multi‐ions electrolyte system may address the challenging issues faced by single alkali or alkaline‐earth metal batteries. [ABSTRACT FROM AUTHOR]

Zinc–air batteries (ZABs) hold potential as clean, cost‐effective, and sustainable energy storage system for the next generation. However, the application of ZABs remains challenging because of their poor rechargeability and low efficiency. The design of efficient bifunctional catalysts toward oxygen reduction reaction (ORR) during discharging and the oxygen evolution reaction (OER) during charging is essential to developing rechargeable ZABs. Transition metal (TM)‐doped carbon (TM‐C) materials stand out from all the available bifunctional catalysts due to the excellent specific surface area, diverse morphological structures , and the multiple metal active sites formed after TM doping. This paper, therefore, focuses on the synthesis, electrochemical properties, and potential mechanism of TM‐C catalysts. To make a novelty and logical statement, the voltage difference (ΔE = Ei = 10 − E1/2) between the ORR/OER catalytic process is employed to categorize different TM‐C catalysts reported in recent years, which are divided into two groups: I (ΔE = 0.7 − 0.9 V) and II (ΔE = 0.5 − 0.7 V). The catalytic mechanisms of bifunctional catalysts are clarified. More ways and ideas for synthesizing high‐performance bifunctional TM‐C catalysts are also provided. Finally, the current problem and prospects of this group materials are presented. [ABSTRACT FROM AUTHOR]

Rechargeable aqueous Zn/δ‐MnO2 batteries are extensively investigated owing to the low cost, safety and eco‐friendliness. However, the charge storage mechanism of δ‐MnO2 electrode is still in debate. In this paper, it is revealed that the Zn2+ intercalation in δ‐MnO2 electrode is an ion exchange process rather than the commonly‐conceived electrochemical process for the first time. Before the discharge/charge process, Zn2+ irreversibly intercalates into the structure of δ‐MnO2. The ion‐exchange mediated irreversible Zn2+ intercalation in δ‐MnO2 has no contribution to the capacity of δ‐MnO2 electrode during cycles. This study further reveals that the electrochemical H+ intercalation/extraction, the electrodissolution of δ‐MnO2 and the electrodissolution‐electrodeposition of vernadite dominate the charge storage process of δ‐MnO2 electrode. These findings shed new light on the fundamental understanding for the reaction mechanism of δ‐MnO2 electrode in aqueous batteries. [ABSTRACT FROM AUTHOR]

Rechargeable batteries that make renewable energy resources feasible for electrification technologies have been extensively investigated. Their corresponding performance is strongly dependent on the structural characteristics and chemical dynamics of internal electrode and electrolyte materials under operating conditions. To enhance battery performance and lifetime, a comprehensive understanding of the structure‐dynamics‐performance correlation of such materials under different working conditions is of great significance. Fortunately, in situ transmission electron microscopy (TEM) encompassing high‐resolution imaging, diffraction, and spectroscopic analysis, offers unprecedented insights into the nano/atomic scale structural changes and degradation pathways of rechargeable battery materials under operational conditions. Such insights are pivotal for a deep‐rooted understanding of reaction mechanisms and the structure‐activity interplay within battery materials. This work, therefore, highlights the advances in in situ TEM's utility in unveiling dynamic chemical and physical changes in real‐time within battery materials of rechargeable batteries. Electrochemical processes and degradation mechanisms are systematically explored and summarized. Moreover, the technical progress, challenges, and valuable insights provided by in situ TEM techniques for addressing critical issues in battery materials are underscored. The work concludes with a discussion of emerging research directions that hold the potential to revolutionize the renewable energy field in the near future. [ABSTRACT FROM AUTHOR]

The development and utilization of electrochemical energy conversion and storage devices can maximize intermittent renewable energy and balance environmental issues. Aqueous metal‐redox bicatalyst batteries, incorporating value‐added electro‐reduction reactions during discharge process at the cathode, are considered a particularly attractive alternative for simultaneous electricity generation and valuable chemical production. In this review, for the first time, a holistic and subtle description of value‐added metal‐redox bicatalyst batteries is made, focusing on recent efforts to optimize the energy conversion/chemical production‐involved cathodic discharging reactions, including CO2 reduction reaction (CO2RR), nitrogen reduction reaction (NRR), nitric oxide reduction reaction (NORR), nitrate reduction reaction (NO3−RR), nitrite reduction reaction (NO2−RR), hydrogen evolution reaction (HER), and acetylene reduction reaction (ARR). A macroscopic understanding of design principles in terms of anodes, cathodes, and reaction parameters is provided. Some mechanism explorations, feasibility analyses, technoeconomic assessments, device combinations, and associated comparisons are involved to deepen the understanding of different systems and evaluate their application prospects. Perspectives on and opportunities for future research directions are also outlined. [ABSTRACT FROM AUTHOR]

As one of the most appealing energy storage technologies, aqueous zinc‐iodine batteries still suffer severe problems such as low energy density, slow iodine conversion kinetics, and polyiodide shuttle. This review summarizes the recent development of Zn─I2 batteries with a focus on the electrochemistry of iodine conversion and the underlying working mechanism. Starting from the fundamentals of Zn─I2 batteries, the electrochemistry of iodine conversion and zinc anode, as well as the scientific problems existing in Zn─I2 batteries are introduced. The concrete strategies dealing with cathode, anode, electrolyte, and separator challenges confronting Zn─I2 batteries are elaborated as well. To deepen the understanding of the electrochemistry of Zn─I2 batteries, the recent important findings of the underlying working mechanism of different Zn─I2 batteries are summarized in detail. Finally, some guidelines and directions for Zn─I2 batteries are also provided. This review is expected to deepen the understanding of Zn─I2 battery electrochemistry and promote their practical applications in the future. [ABSTRACT FROM AUTHOR]

The growing demand for sustainable energy storage devices requires rechargeable lithium‐ion batteries (LIBs) with higher specific capacity and stricter safety standards. Ni‐rich layered transition metal oxides outperform other cathode materials and have attracted much attention in both academia and industry. Lithium‐ion batteries composed of Ni‐rich layered cathodes and graphite anodes (or Li‐metal anodes) are suitable to meet the energy requirements of the next generation of rechargeable batteries. However, the instability of Ni‐rich cathodes poses serious challenges to large‐scale commercialization. This paper reviews various degradation processes occurring at the cathode, anode, and electrolyte in Ni‐rich cathode‐based LIBs. It highlights the recent achievements in developing new stabilization strategies for the various battery components in future Ni‐rich cathode‐based LIBs. [ABSTRACT FROM AUTHOR]

Lithium‐ion batteries (LIBs) and beyond‐LIB systems exhibit properties that are determined by electrochemical reactions occurring in their four essential components—the cathode, anode, electrolyte, and separator. Advanced analytical methods such as differential electrochemical mass spectrometry (DEMS) can assist in understanding the electrochemical behavior, which can help in advancing battery technologies. Recent studies have shown that the DEMS‐enabled real‐time gas analysis of electrochemical reactions can provide valuable information on aspects such as gaseous reactants or (side) products, which cannot be obtained appropriately through other characterization techniques. This review aims to provide a comprehensive overview of the latest developments and advancements in the use of DEMS as a rapid, operando gas‐monitoring method for advanced rechargeable battery systems. Moreover, the significance of DEMS in current and future battery development is also discussed and insights are provided into the various battery chemistries that can benefit from DEMS applications. This review is intended to help readers understand the potential of DEMS to drive innovation in the battery industry. [ABSTRACT FROM AUTHOR]

Zn powder is considered as a potential Zn metal anode for aqueous Zn‐ion batteries. However, restricted ion/electron transfer and volume effect‐caused electrical contact failure in conventional polymer binder composited Zn powder anodes deteriorate their electrochemical performance. Here, a high‐performance soft solid‐like viscoelastic Zn powder composite anode is proposed based on an oligomer gluing strategy. Benefiting from the viscoelastic properties, the soft‐solid Zn powder composite (ss‐ZnP) anode has significantly enhanced charge transfer, alleviated volume effect, and homogenized interfacial electric field, leading to fast plating/stripping kinetics and dendrite‐free deposition morphology. Furthermore, the assembled NH4V4O10‖ss‐ZnP full cell delivers higher capacity (510 mAh g−1 at 0.1A g−1, 300 mAh g−1 at 1A g−1) and longer lifespan up to 500 cycles at 1 A g−1, superior to conventional polymer binder composited Zn powder anode and other reported rheological Zn powder‐based anodes. Apart from the electrochemical merits, this soft matter‐based design also endows the ss‐ZnP electrode with free‐standing and malleable properties which greatly expand its practical application. [ABSTRACT FROM AUTHOR]

Polyaniline is the most famous conducting polymer and also a promising organic cathode material for rechargeable batteries, however, it has demonstrated poor utilization of its theoretical capacity (294 mAh g−1) and inferior cycling stability in previous studies. Herein, for the first time, its fully reduced form, i.e., leucoemeraldine base (LB), is studied as an alternative to the commonly used emeraldine salt and base (ES and EB). For the three different forms, the precise structures are carefully determined, and the electrochemical performance are systematically investigated. Within 2.0−4.3 V, LB realizes almost full capacity utilization (92%) that is much superior to those of ES and EB. Within 2.0−4.2 V, it shows both high reversible capacity (277 mAh g−1) and cycling stability (84% capacity retention after 1000 cycles). The combination of electrochemical analysis, density functional theory calculation, and ex situ characterization reveals that the capacity utilization is positively associated with the pristine proportion of ─NH─ groups, and the capacity fading is caused by the irreversible electrochemical deprotonation at high charge potential. This work promotes both the electrochemical performance and mechanistic understanding of polyaniline to a new stage, towards practical application in energy storage devices as a low‐cost, high‐performance, sustainable, and green cathode material. [ABSTRACT FROM AUTHOR]

Reversibility, usually evaluated by Coulombic efficiency (CE) and limited by dendrite growth, has become the major roadblock toward the widespread commercialization of zincion batteries. Tailoring the Zn deposition behavior is vital to prevent dendrite growth. In this work, the facet‐terminator serine is introduced to modulate the interface and obstruct the rampant growth of the Zn (100) plane. The serine cation (Ser+) is revealed to preferentially adsorb onto the electrode/electrolyte interface, suppressing the interfacial parasitic reaction. Theoretical analysis and postmortem/operando experimental techniques indicate that the Ser+ bestows (100)‐dominated morphology to zinc anodes, enabling a highly reversible and dendrite‐free Zn anode. These features endow the Zn anode with a long cyclic life of more than 800 h for Zn//Zn batteries and a high average Coulombic efficiency of 99.8% at 5 mA cm−2 and 5 mAh cm−2 for Zn//Cu batteries. When assembling with commercial V2O5, the full battery delivers a high capacity of 345.1 mAh g−1 at 5 A g−1 with a retention of 74.1% over 2000 cycles. [ABSTRACT FROM AUTHOR]

The remarkable surge in energy demand has compelled the quest for high‐energy‐density battery systems. The Li–O2 battery (LOB) and Li–air battery (LAB), owing to their extremely high theoretical energy density, have attracted extensive research in the past two decades. The commercial development of LOB is hampered due to the numerous challenges its components present. Ionic liquids (ILs) are considered potential electrolyte solvents of LOBs and LABs due to their excellent electrochemical stability, thermal stability, non‐flammability, low flammability, and O2 solubility. In addition to electrolyte solvents, ILs also have other applications in LOB and LAB systems. This review reports the progress of IL‐based LOBs and LABs over the years since treported for the first time in 2005. The impact of the physiochemical properties of ILs on the performance of LOB and LAB at various operating conditions is thoroughly discussed. The various methodologies are also summarized that are employed to tune ILs' physiochemical properties to render them more favorable for rechargeable lithium batteries. Tunable properties of ILs create the possibility of designing cost‐effective batteries with excellent safety, high energy density and high power density, and long‐term stability. [ABSTRACT FROM AUTHOR]

To meet the demand for high‐energy‐density batteries, alloy‐type and conversion‐type anode materials have attracted growing attention due to their high specific capacity. However, the huge irreversible lithium loss during initial cycling significantly reduces the energy density of the full cell, which limits their practical applications. Fortunately, various anode prelithiation techniques have been developed to compensate for the initial lithium loss. At the same time, the cathode prelithiation has been proposed and demonstrated remarkable enhancement in the electrochemical performance, along with excellent scalability and compatibility with the existing battery production processes. Here, recent advances are reviewed in the prelithiation of both anodes and cathodes, and the key challenges are discussed in front of their practical applications. It is aimed to provide better recommendations and assistance for its large‐scale practical applications. [ABSTRACT FROM AUTHOR]

Non‐equilibrium defects often dictate the macroscopic properties of materials. They largely define the reversibility and kinetics of processes in intercalation hosts in rechargeable batteries. Recently, imaging methods have demonstrated that transient dislocations briefly appear in intercalation hosts during ion diffusion. Despite new discoveries, the understanding of impact, formation and self‐healing mechanisms of transient defects, including and beyond dislocations, is lacking. Here, operando X‐ray Bragg Coherent Diffractive Imaging (BCDI) and diffraction peak analysis capture the stages of formation of a unique metastable domain boundary, defect self‐healing, and resolve the local impact of defects on ionic diffusion in NaxNi1−yMnyO2 intercalation hosts in a charging sodium‐ion battery. Results, applicable to a wide range of layered intercalation materials due to the shared nature of framework layers, elucidate new dynamics of transient defects and their connection to macroscopic properties, and suggest how to control the nanostructure dynamics. [ABSTRACT FROM AUTHOR]

Aqueous zinc‐ion batteries (ZIBs) enjoy a good reputation for being safe, affordable to produce, and ecologically friendly due to the use of water‐based electrolytes. The main factors restricting the development of ZIBs, however, are the negative effects of dendrite deposition on the zinc anode and the dissolution of common cathodes such as Mn and V‐based cathodes. Various techniques have been used to address these issues, including regulating the electrolyte concentration or solvation structure, developing a coating or current collector to lessen anode dendrite growth, and improving the structural stability of the cathode. Recently, functionalized separator strategies have gained popularity as effective ways to improve ZIB performance. The use of a functionalized separator is also a practical technique to save costs and increase the volumetric energy density of the battery by substituting a functionalized separator for the usual thick and expensive glass fiber separator. The development of functionalized separators in ZIBs is the subject of ongoing research, and this work presents the most recent findings in a systematic manner, focusing on both the effects and the methods to prepare or modify them. Finally, a brief explanation of the constraints and future potential of current functionalized separator development is provided. [ABSTRACT FROM AUTHOR]

Metal–N2 batteries attract considerable research attention due to the dual‐functional characteristics applied in energy storage and conversion, as well as electrochemical artificial NH3 yield. Nonetheless, it has been found that not all kinds of metal–N2 batteries are suitable for combining the above two applications. Herein, recent advances in metal–N2 batteries are summarized. First, the electrochemical reaction mechanisms for all types of metal–N2 batteries, including organic Li/Na/Al–N2 batteries and aqueous Zn/Al–N2 batteries are discussed, and then, a critical assessment of current challenges and future applications is provided. Considering the different electrochemical reaction mechanism in the metal–N2 batteries, the electrocatalytic performance for the reported catalyst cathodes is summarized and compared. Then, a multi‐dimensional feasibility and strategy analysis for the developments of rechargeable aqueous Zn–N2 batteries is provided, including the three dimensions of cathode catalyst, electrolyte, and metal anodes. Last, specific suggestions and ideas for the further developments of the rechargeable aqueous Zn–N2 batteries are put forward, with the hope of inspiring the further developments for the green, sustainable, and high‐energy‐density metal–N2 systems in the future. [ABSTRACT FROM AUTHOR]

Li‐ion batteries (LIBs) that promise both safety and high energy density are critical for a new‐energy future. However, recent studies on battery thermal runaway (TR) suggest that the higher the energy is compressed in a battery, the thermal accidents with fires and explosions can occur in a more catastrophic way. This "trade‐off" between energy density and safety poses challenging obstacles toward the future applications of the developing high‐energy chemistries. Herein, the thermal studies on the most appealing high‐energy (HE)‐LIB chemistries are carefully reviewed. The TR characters of the HE‐LIBs, the material thermal failure behaviors as well as the underneath reaction mechanisms, and the most advanced TR mitigation technologies are comprehensively summarized. Moreover, the effectiveness of different TR mitigation routes is analyzed. Based on the analysis, the main challenges for TR mitigation in HE chemistries are further explained. Finally, opinions on the future TR mechanism studies and the promising safety design routes to overcome this intrinsic "trade‐off" between high energy and safety are presented. [ABSTRACT FROM AUTHOR]

Li‐ion batteries (LIBs) that promise both safety and high energy density are critical for a new‐energy future. However, recent studies on battery thermal runaway (TR) suggest that the higher the energy is compressed in a battery, the thermal accidents with fires and explosions can occur in a more catastrophic way. This "trade‐off" between energy density and safety poses challenging obstacles toward the future applications of the developing high‐energy chemistries. Herein, the thermal studies on the most appealing high‐energy (HE)‐LIB chemistries are carefully reviewed. The TR characters of the HE‐LIBs, the material thermal failure behaviors as well as the underneath reaction mechanisms, and the most advanced TR mitigation technologies are comprehensively summarized. Moreover, the effectiveness of different TR mitigation routes is analyzed. Based on the analysis, the main challenges for TR mitigation in HE chemistries are further explained. Finally, opinions on the future TR mechanism studies and the promising safety design routes to overcome this intrinsic "trade‐off" between high energy and safety are presented. [ABSTRACT FROM AUTHOR]

For the proper design and evaluation of next‐generation lithium‐ion batteries, different physical‐chemical scales have to be considered. Taking into account the electrochemical principles and methods that govern the different processes occurring in the battery, the present review describes the main theoretical electrochemical and thermal models that allow simulation of the performance of lithium‐ion batteries, including different materials and components (electrodes and separators) and battery geometries. As the separator plays an essential role in the performance and safety of lithium‐ion batteries, the recent theoretical simulation work for this battery component are shown, with particular emphasis on morphology, dendrite growth, ionic transport, and mechanical properties. Further theoretical simulations and modeling of this battery component are still required for improving performance, taking into consideration varying geometric parameters such as pore size, porosity, and tortuosity as well as the optimization of the lithium diffusion process and ionic conductivity value. Theoretical simulations of battery separators will play an essential role in the new generation of lithium‐ion batteries, allowing the improvement of their performance while reducing experimental probes and time. [ABSTRACT FROM AUTHOR]

Rechargeable aqueous zinc‐iodine batteries (ZIBs) are considered a promising newly‐developing energy‐storage system, but the corrosion and dendritic growth occurring on the anode seriously hinder their future application. Here, the corrosion mechanism of polyiodide is revealed in detail, showing that it can spontaneously react with zinc and cause rapid battery failure. To address this issue, a sulfonate‐rich ion‐exchange layer (SC‐PSS) is purposely constructed to modulate the transport and reaction chemistry of polyiodide and Zn2+ at the zinc/electrolyte interface. The resulting ZIBs can work properly over 6000 cycles with high‐capacity retention (90.2%) and reversibility (99.89%). Theoretical calculations and experimental characterization reveal that the SC‐PPS layer blocks polyiodide permeation through electrostatic repulsion, while facilitating desolvation of Zn(H2O)62+ and restricting undesirable 2D diffusion of Zn2+ by chemisorption. [ABSTRACT FROM AUTHOR]

Metallic lithium is a fascinating anode for the next‐generation energy‐dense rechargeable batteries owing to the highest theoretical specific capacity and lowest electrochemical potential. Nevertheless, sluggish desolvation kinetics and notorious dendritic growth hinder its electrochemical performance and safe operation. Herein, an interlamellar Li+ conductor of Ag‐montmorillonite (AMMT) is proposed as an interfacial ion‐transport‐rectifying pump to induce the rapid and reversible plating/stripping of Li metal. Joint experimental and computational analyses reveal that the AMMT pump with negative charge layers and inherent channels can lower the desolvation energy and boost Li+ transport. The resultant Li anode is endowed with a low nucleation barrier (22.2 mV) and dendrite‐free features, leading to high plating/stripping density (8 mA cm‐2) and long lifespan (2500 h). Moreover, the corresponding Li||LiFePO4 batteries achieve a steady circulation (500 cycles@82%, 1 C) with a low N/P ratio. This strategy offers a fresh insight into constructing robust multifunctional electrolyte/Li anode interface for Li metal batteries. [ABSTRACT FROM AUTHOR]

Lithium‐ion/sodium‐ion batteries are the most advanced energy storage devices, but the structural evolution of electrode materials, electrolyte decomposition, the growth of Li/Na dendrites and the generation of heat and gas inside batteries represent serious safety issues. Therefore, it is necessary to real time monitor the parameter changes inside these devices. Herein, the recent important progress in a variety of advanced intelligent detection techniques based on the detection of heat, gas, and strain is introduced and discussed. The perfect combination of electrochemical parameters and these advanced intelligent sensing techniques allows the monitoring of the dynamic chemical and thermal evolution during a cell's operation without any impact, which is crucial to making meaningful advancements in energy storage devices. This work provide access to advanced diagnostic tools to guide the rational design of high‐safety batteries. [ABSTRACT FROM AUTHOR]

Phosphate (sulfate) fluorides have attracted much attention recently as potential positive electrode materials for rechargeable batteries. However, they are broadly referred to fluorophosphates and fluorosulfates by the community. This nomenclature inaccuracy is probably lowering the visibility of papers dealing with "true" fluorophosphates/fluorosulfates and may lead to some confusion about the structural peculiarities of both families of compounds. [ABSTRACT FROM AUTHOR]

High theoretical specific energy of rechargeable lithium–oxygen (Li–O2) batteries makes them very promising in the development of long driving range electric vehicles and energy storage on large‐scale. However, the large polarization and poor cycling stability associated with insufficient catalytic cathodes and the insulating nature of discharge products limit their practical applications. Here, the fabrication of a trimetallic CoFeCe oxide with an amorphous/crystalline heterostructure acting as an electrocatalyst for the Li–O2 battery cathode is reported. The best‐performing CoFeCe oxide cathode manages to deliver an initial discharge capacity of 12 340 mAh g−1, while maintaining an impressively enhanced cyclic stability over 2900 h at 100 mA g−1. As revealed by combined experimental results and density functional theory (DFT) analysis, synergistic interaction between oxide components, amorphous–crystalline domains, unique heterostructure with minimized lattice mismatch, and the enhanced adsorption of the key intermediate LiO2 are critical factors in boosting the electrocatalytic activity of CoFeCe toward the formation of decomposable Li2O2. This work offers a new insight to rationally design and synthesize an effective multimetal oxide electrocatalyst for the Li–O2 battery cathode. [ABSTRACT FROM AUTHOR]

Sulfur‐based batteries are regarded as potent candidates for next‐generation high‐energy and low‐cost energy storage systems. However, sulfur‐based batteries still face substantial obstacles on the cathode side (e.g., low conductivity and sluggish reaction kinetics of sulfur) and the anode side (e.g., dendrite growth), severely hindering their utilization. MXenes (i.e., 2D transition metal carbides, nitrides, and carbonitrides), as an emerging member of the 2D material family, possess unique electrochemical and electronic properties, which make them attractive materials to enhance the performance of sulfur‐based batteries. In this article, a comprehensive review of the research progress on using MXenes in sulfur‐based batteries is provided. The basics of MXene and sulfur‐based batteries are introduced first, wherein the merits of applying MXenes in sulfur‐based batteries are discussed. Subsequently, the progress in this field is systematically summarized in terms of the roles of MXene in sulfur‐based batteries, including MXene as sulfur host, MXene‐based composite as sulfur host, MXene‐based separator modification, and MXene‐based advanced electrodes. In the end, recommendations for specific future research directions to advance the development of MXenes for sulfur‐based batteries are outlined. [ABSTRACT FROM AUTHOR]

Sulfide‐based all‐solid‐state batteries (ASSBs) are one of the most promising energy storage devices due to their high energy density and good safety. However, due to the volume (stress) changes of the solid active materials during the charging and discharging process, the generation and evolution of electrochemomechanical stresses are becoming serious and unavoidable problems during the operation of all‐solid‐state batteries due to the lack of a liquid electrolyte to partially buffer the stress generated in the electrodes. To understand these electrochemo‐mechanical effects, including the origins and evolution of mechanical or internal stresses, it is necessary to develop some highly sensitive probing techniques to measure them precisely and bridge the relationship between the electrochemical reaction process and internal stress evolution. Herein, recent progress on uncovering the origins of the internal stresses, the working principle and experimental devices for stress measurement, and the application of those stress‐measuring techniques in the study of electrochemical reactions in sulfide‐based ASSBs are briefly summarized and overviewed. The investigation of precise and operando monitoring techniques and strategies for suppressing or relaxing these electrochemomechanical stresses will be an important direction in future solid‐state batteries. [ABSTRACT FROM AUTHOR]

The garnet‐type phase Li7La3Zr2O12 (LLZO) attracts significant attention as an oxide solid electrolyte to enable safe and robust solid‐state batteries (SSBs) with potentially high energy density. However, while significant progress has been made in demonstrating compatibility with Li metal, integrating LLZO into composite cathodes remains a challenge. The current perspective focuses on the critical issues that need to be addressed to achieve the ultimate goal of an all‐solid‐state LLZO‐based battery that delivers safety, durability, and pack‐level performance characteristics that are unobtainable with state‐of‐the‐art Li‐ion batteries. This perspective complements existing reviews of solid/solid interfaces with more emphasis on understanding numerous homo‐ and heteroionic interfaces in a pure oxide‐based SSB and the various phenomena that accompany the evolution of the chemical, electrochemical, structural, morphological, and mechanical properties of those interfaces during processing and operation. Finally, the insights gained from a comprehensive literature survey of LLZO–cathode interfaces are used to guide efforts for the development of LLZO‐based SSBs. [ABSTRACT FROM AUTHOR]

In pursuit of reducing environmental impact during battery manufacture, the utilization of nontoxic and renewable materials is essential for building a sustainable future. As one of the most intensively investigated biomaterials, proteins have recently been applied in various high‐performance rechargeable batteries. In this review, the opportunities and challenges of using protein‐based materials for high‐performance energy storage devices are discussed. Recent developments of directly using proteins as active components (e.g., electrolytes, separators, catalysts or binders) in rechargeable batteries are summarized. The advantages and disadvantages of using proteins are compared with the traditional counterparts, and the working mechanisms when using proteins to improve the electrochemical performances of rechargeable batteries are elucidated. Finally, the future development of applying biomaterials to build better batteries is predicted. [ABSTRACT FROM AUTHOR]

An integrated preparation of a low-cost composite gel-polymer/glass-fiber electrolyte with poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) reinforced by a glass-fiber paper and modified by a polydopamine coating to tune the mechanical and surface properties of PVDF-HFP is shown to be applicable to a sodium-ion battery. The composite polymer matrix exhibits excellent mechanical strength and thermal stability up to 200 °C. After saturating with a liquid electrolyte, a wide electrochemical window and high ionic conductivity is obtained for the composite gel-polymer/glass-fiber electrolyte. When tested in a sodium-ion battery with Na2MnFe(CN)6 as cathode, the rate capability, cycling performance, and coulombic efficiency are significantly improved. The results suggest that the composite polymer electrolyte is a very attractive separator for a large-scale battery system where safety and cost are the main concerns. [ABSTRACT FROM AUTHOR]

An integrated preparation of a low-cost composite gel-polymer/glass-fiber electrolyte with poly(vinylidene fluoride- co-hexafluoropropylene) (PVDF-HFP) reinforced by a glass-fiber paper and modified by a polydopamine coating to tune the mechanical and surface properties of PVDF-HFP is shown to be applicable to a sodium-ion battery. The composite polymer matrix exhibits excellent mechanical strength and thermal stability up to 200 °C. After saturating with a liquid electrolyte, a wide electrochemical window and high ionic conductivity is obtained for the composite gel-polymer/glass-fiber electrolyte. When tested in a sodium-ion battery with Na2MnFe(CN)6 as cathode, the rate capability, cycling performance, and coulombic efficiency are significantly improved. The results suggest that the composite polymer electrolyte is a very attractive separator for a large-scale battery system where safety and cost are the main concerns. [ABSTRACT FROM AUTHOR]

Aqueous zinc–ion batteries (ZIBs) have been promptly developed as a competitive and promising system for future large‐scale energy storage. In recent years, vanadium (V)‐based compounds, with diversity of valences and high electrochemical‐activity, have been widely studied as cathodes for aqueous ZIBs because of their rich reserves and high theoretical capacity. However, the stubborn issues including low conductivity and sluggish kinetics, plague their smooth application in aqueous ZIBs. Among various countermeasures, defect engineering is believed as an effective method to alleviate the above limitations. This review highlights the challenges of different V‐based cathode materials (e.g., vanadium oxides and vanadates) and summarizes the advances in defect engineering strategies including types and effects of the defects, designed strategies, and characterization techniques for high‐energy ZIBs. Finally, several sound prospects in this fervent field are also rationally proposed for fundamental research and practical application. [ABSTRACT FROM AUTHOR]

All‐solid‐state lithium metal batteries are prominent candidates for next‐generation batteries with high energy density and low safety risks. However, the traditional planar contact between Li metal and solid‐state electrolytes (SSEs) exhibits substantive void formation and large interfacial morphological fluctuation, causing poor interfacial stability. Here, an interdigitated Li‐solid polymer electrolyte framework (I‐Li@SPE), a pioneering demonstration of 3D interface in polymer‐based all‐solid‐state batteries, is designed, transferring the Li‐SSE interfacial contact from planar to 3D for enhanced interfacial integrity. A smooth and intact 3D Li‐SSE interfacial contact after repeated cycling that precedes planar Li‐SSE contact, is shown. COMSOL simulation indicates I‐Li@SPE reduces local current densities by more than 40% and moderates interfacial variation by more than 50%. As a result, I‐Li@SPE achieves high critical current density of 1 mA cm−2, as well as promising high areal capacity cycling of 4 mAh cm−2 at 0.4 mA cm−2. This work provides a new structure for Li‐SSE composite fabrication and high‐capacity solid‐state Li batteries. [ABSTRACT FROM AUTHOR]

Lithium metal anodes are regarded as the most promising candidate for rechargeable lithium‐based batteries, but uncontrollable Li dendrites hinder further applications. Here, sine‐wave analogous MXene (Ti3C2Tx) (SWA‐MXene) layers are produced by spreading aqueous MXene dispersion onto the sectional surface of a metallic coil and subsequently drying at room temperature. COMSOL Multiphysics simulations demonstrate that the low curvature in SWA‐MXene layers homogenizes the distributions of lithium ions and electric field, efficiently eliminating the lightning‐rod effect on the surface of aligned electrodes in the process of Li deposition. As a result, the flexible SWA‐MXene layers show a low overpotential for lithium nucleation (≈13.5 mV at 0.05 mA cm−2) and deep plating–stripping capacities up to 40 mAh cm−2, as well as a long cycle life up to 1250 h. Full cells consisting of a SWA‐MXene–Li anode and a LiFePO4 cathode also exhibit a durable cycle life up to 420 cycles at 1088 mA g−1. [ABSTRACT FROM AUTHOR]

Electrolytes play a critical role in stabilizing highly reactive lithium‐metal anodes (LMAs) and high‐voltage cathodes for rechargeable lithium‐metal batteries (LMBs). Localized high concentration electrolytes (LHCEs) have achieved remarkable success in the context of LMBs. However, the state‐of‐the‐art LHCEs are based on LiFSI salt, which is prohibitively expensive. Here, the utility of low‐cost LiPF6 salt in localized saturated electrolytes (LSEs) with a series of solvents and diluents in LMBs with cobalt‐free LiNiO2 cathode is systematically explored. Experimental and theoretical analyses reveal that the unique solvation structure formed not only changes the distribution of solvents and anions but also alters the atom–atom distances within them, leading to different reduction and oxidation stabilities compared to low‐concentration electrolytes. In addition, LSEs help form LiF‐rich interphase layers on the LMA and LiNiO2 cathode, protecting the electrodes from degradation during cycling. Different LSEs also lead to differences in lithium plating morphology and impedance buildup during cycling, impacting the performance of LMBs. The solvent and diluent must be carefully selected for compatibility with a lithium salt when developing LHCEs and LSEs for LMBs. [ABSTRACT FROM AUTHOR]

Machine learning (ML)‐based approaches to battery design are relatively new but demonstrate significant promise for accelerating the timeline for new materials discovery, process optimization, and cell lifetime prediction. Battery modeling represents an interesting and unconventional application area for ML, as datasets are often small but some degree of physical understanding of the underlying processes may exist. This review article provides discussion and analysis of several important and increasingly common questions: how ML‐based battery modeling works, how much data are required, how to judge model performance, and recommendations for building models in the small data regime. This article begins with an introduction to ML in general, highlighting several important concepts for small data applications. Previous ionic conductivity modeling efforts are discussed in depth as a case study to illustrate these modeling concepts. Finally, an overview of modeling efforts in major areas of battery design is provided and several areas for promising future efforts are identified, within the context of typical small data constraints. [ABSTRACT FROM AUTHOR]

Rechargeable aluminum ion batteries (AIBs) are one of the most promising battery technologies for future large‐scale energy storage due to their high theoretical volumetric capacity, low‐cost, and high safety. However, the low capacity of the intercalation‐type cathode materials reduces the competitiveness of AIBs in practical applications. Herein, a conversion‐type FeF3‐expanded graphite (EG) composite is synthesized as a novel cathode material for AIBs with good conductivity and cycle stability. Combined with the introduction of a single‐wall carbon nanotube modified separator, the shuttle effect of the intermediate product, FeCl2, is significantly restrained. Moreover, enhanced coulombic efficiency and reversible capacity are achieved. The AIB exhibits a satisfying reversible specific capacity of 266 mAh g−1 at 60 mA g−1 after 200 cycles, and good Coulombic efficiency of nearly 100% after 400 cycles at a current density of 100 mA g−1. Ex situ X‐ray diffraction and X‐ray photoelectron spectroscopy are applied to explore the energy storage mechanism of FeF3 in AIBs. The results reveal that the intercalation of Al3+ species and the reduction of Fe3+ species occurrs in the discharge process. These findings are meaningful for the fundamental understanding of the FeF3 cathode for AIBs and provide unprecedented insight into novel conversion type cathode materials for AIBs. [ABSTRACT FROM AUTHOR]

Abstract: Hard carbon is regarded as the most promising anode material for commercialization of Na ion batteries because of its high capacity and low cost. At present, the practical utilization of hard carbon anodes is largely limited by the low initial Coulombic efficiency (ICE). Na ions have been found to adopt an adsorption–insertion storage mechanism. In this paper a systematic way to control the defect concentration and porosity of hard carbon with similar overall architectures is shown. This study elucidates that the defects in the graphite layers are directly related to the ICE as they would trap Na ions and create a repulsive electric field for other Na ions so as to shorten the low‐voltage intercalation capacity. The obtained low defect and porosity hard carbon electrode has achieved the highest ICE of 86.1% (94.5% for pure hard carbon material by subtracting that of the conductive carbon black), reversible capacity of 361 mA h g−1, and excellent cycle stability (93.4% of capacity retention over 100 cycles). This result sheds light on feasible design principles for high performance Na storage hard carbon: suitable carbon layer distance and defect free graphitic layers. [ABSTRACT FROM AUTHOR]

Abstract: This paper reports the rational assembly of novel hollow porous carbon nanospheres (HPCNSs) as the hosts of phosphorous (P) active materials for high‐performance sodium‐ion batteries (SIBs). The vaporization‐condensation process is employed to synthesize P/C composites, which is elucidated by both theories and experiments to achieve optimized designs. The combined molecular dynamics simulations and density functional theory calculations indicate that the morphologies of polymeric P4 and the P loading in the P/C composites depend mainly on the pore size and surface condition of carbon supports. Micropores of 1–2 nm in diameter and oxygenated functional groups attached on carbon surface are essential for achieving high P loading and excellent structural stability. In light of these findings, HPCNS/amorphous red phosphorus composites with enhanced structural/functional features are synthesized, which present an extremely low volume expansion of ≈67.3% during cycles, much smaller than the commercial red P's theoretical value of ≈300%. The composite anodes deliver an exceptional sodium storage capacity and remarkable long‐life cyclic stability with capacity retention over 76% after 1000 cycles. This work signifies the importance of rational design of electrode materials based on accurate theoretical predictions and sheds light on future development of cost‐effective P/C composite anodes for commercially viable SIBs. [ABSTRACT FROM AUTHOR]

Keywords: calcium metal; muti-ions; rechargeable batteries; relay insertion/extraction; tailorable window voltage EN calcium metal muti-ions rechargeable batteries relay insertion/extraction tailorable window voltage 1 1 1 03/13/21 20210311 NES 210311 In article number 2003685, Chengxin Wang and co-workers realize voltage tailorable room-temperature Ca-metal batteries with high voltage stability up to 4.7 V, wide window voltage adaptability of 0.005-4.9 V vs. Ca-Metal Batteries: Multi-Ions Electrolyte Enabled High Performance Voltage Tailorable Room-Temperature Ca-Metal Batteries (Adv. Calcium metal, muti-ions, rechargeable batteries, relay insertion/extraction, tailorable window voltage. [Extracted from the article]

Rechargeable aqueous batteries are considered to be one of the most effective energy storage technologies to balance the cost‐efficiency, safety, and energy/power demands. The further progress of aqueous batteries with high energy density is needed to meet the ever‐increasing energy‐storage demands. This review highlights the strategies proposed so far to pursue the high energy density aqueous batteries, including the aspects of the electrolytes (from concentrated to dilute), the electrode chemistry (from inserted to converted), the cathode materials (from inorganic to organic), the anode materials (from compound to metallic), and the battery configurations (from integrated to decoupled). Critical appraisals of the emerging electrochemistry are presented for addressing the key issues in boosting the energy densities. Finally, the authors render insights into the future development of high‐energy aqueous batteries. [ABSTRACT FROM AUTHOR]

The development of new batteries has historically been achieved through discovery and development cycles based on the intuition of the researcher, followed by experimental trial and error—often helped along by serendipitous breakthroughs. Meanwhile, it is evident that new strategies are needed to master the ever‐growing complexity in the development of battery systems, and to fast‐track the transfer of findings from the laboratory into commercially viable products. This review gives an overview over the future needs and the current state‐of‐the art of five research pillars of the European Large‐Scale Research Initiative BATTERY 2030+, namely 1) Battery Interface Genome in combination with a Materials Acceleration Platform (BIG‐MAP), progress toward the development of 2) self‐healing battery materials, and methods for operando, 3) sensing to monitor battery health. These subjects are complemented by an overview over current and up‐coming strategies to optimize 4) manufacturability of batteries and efforts toward development of a circular battery economy through implementation of 5) recyclability aspects in the design of the battery. [ABSTRACT FROM AUTHOR]

Editorial to the Special Issue: How to Reinvent the Ways to Invent the Batteries of the Future - the Battery 2030+ Large-Scale Research Initiative Roadmap Since this was published in 2018, the ETIP Batteries Europe recently launched six different roadmaps along the full battery value chain, SP [ sp 4 SP ] sp describing the long-term expectations for future battery chemistries, which has a more updated view on the battery landscape compared to the earlier presented SET-Plan. Globally, there is a range of battery roadmaps and strategic action plans, all more or less focusing on different chemistries and new battery concepts outlining both timelines and expectations in terms of performances. [Extracted from the article]

This roadmap presents the transformational research ideas proposed by "BATTERY 2030+," the European large‐scale research initiative for future battery chemistries. A "chemistry‐neutral" roadmap to advance battery research, particularly at low technology readiness levels, is outlined, with a time horizon of more than ten years. The roadmap is centered around six themes: 1) accelerated materials discovery platform, 2) battery interface genome, with the integration of smart functionalities such as 3) sensing and 4) self‐healing processes. Beyond chemistry related aspects also include crosscutting research regarding 5) manufacturability and 6) recyclability. This roadmap should be seen as an enabling complement to the global battery roadmaps which focus on expected ultrahigh battery performance, especially for the future of transport. Batteries are used in many applications and are considered to be one technology necessary to reach the climate goals. Currently the market is dominated by lithium‐ion batteries, which perform well, but despite new generations coming in the near future, they will soon approach their performance limits. Without major breakthroughs, battery performance and production requirements will not be sufficient to enable the building of a climate‐neutral society. Through this "chemistry neutral" approach a generic toolbox transforming the way batteries are developed, designed and manufactured, will be created. [ABSTRACT FROM AUTHOR]

BATTERY 2030+ targets the development of a chemistry neutral platform for accelerating the development of new sustainable high‐performance batteries. Here, a description is given of how the AI‐assisted toolkits and methodologies developed in BATTERY 2030+ can be transferred and applied to representative examples of future battery chemistries, materials, and concepts. This perspective highlights some of the main scientific and technological challenges facing emerging low‐technology readiness level (TRL) battery chemistries and concepts, and specifically how the AI‐assisted toolkit developed within BIG‐MAP and other BATTERY 2030+ projects can be applied to resolve these. The methodological perspectives and challenges in areas like predictive long time‐ and length‐scale simulations of multi‐species systems, dynamic processes at battery interfaces, deep learned multi‐scaling and explainable AI, as well as AI‐assisted materials characterization, self‐driving labs, closed‐loop optimization, and AI for advanced sensing and self‐healing are introduced. A description is given of tools and modules can be transferred to be applied to a select set of emerging low‐TRL battery chemistries and concepts covering multivalent anodes, metal‐sulfur/oxygen systems, non‐crystalline, nano‐structured and disordered systems, organic battery materials, and bulk vs. interface‐limited batteries. [ABSTRACT FROM AUTHOR]

Complex battery degradation is an interplay of different processes correlated to the thermodynamic, chemical, and mechanical instability of materials. Their degradation kinetics and mechanisms are functions of several intrinsic and environmental conditions. The degradation of the battery cell can be minimized by using preventive steps, like artificial interphases, coatings, additives, or materials that operate within the thermodynamic stability voltage window. Like in most systems/applications degradation processes/aging cannot be avoided since battery cells operate in different environments. Self‐healing functionalities have been proved in different areas of material science and they can significantly improve the performance of battery cells. Some of them have been demonstrated on the laboratory scale, while other degradation processes have been tackled only by the development of preventive approaches. Since self‐healing functionalities add additional weight and cost to the battery cell, directions of development should be focused on modification of nonactive materials, preferably based on biosourced materials to lower environmental impact. Important issues include detection of degradation using sensors and the vectorization of self‐healing components and their controlled release. In addition to this, a triggering process of extrinsic self‐healing components together with manufacturability and recyclability should be considered from the early stages of the development phase. [ABSTRACT FROM AUTHOR]

In recent years, modeling and simulation of materials have become indispensable to complement experiments in materials design. High‐throughput simulations increasingly aid researchers in selecting the most promising materials for experimental studies or by providing insights inaccessible by experiment. However, this often requires multiple simulation tools to meet the modeling goal. As a result, methods and tools are needed to enable extensive‐scale simulations with streamlined execution of all tasks within a complex simulation protocol, including the transfer and adaptation of data between calculations. These methods should allow rapid prototyping of new protocols and proper documentation of the process. Here an overview of the benefits and challenges of workflow engineering in virtual material design is presented. Furthermore, a selection of prominent scientific workflow frameworks used for the research in the BATTERY 2030+ project is presented. Their strengths and weaknesses as well as a selection of use cases in which workflow frameworks significantly contributed to the respective studies are discussed. [ABSTRACT FROM AUTHOR]

Lithium–sulfur batteries have aroused great interest in the context of rechargeable batteries, while the shuttle effect and sluggish conversion kinetics severely handicap their development. Defect engineering, which can adjust the electronic structures of electrocatalyst, and thus affect the surface adsorption and catalytic process, has been recognized as a good strategy to solve the above problems. However, research on phosphorus vacancies has been rarely reported, and how phosphorus vacancies affect battery performance remains unclear. Herein, CoP with phosphorus vacancies (CoP‐Vp) is fabricated to study the enhancement mechanism of phosphorus vacancies in Li–S chemistry. The derived CoP‐Vp features a low Co‐P coordination number and the introduced phosphorus vacancies mainly exist in the form of clusters. The obtained CoP‐Vp can reinforce the affinity to lithium polysulfides (LiPSs) and thus the shuttle effect can be restrained. In addition, the reduced reaction energy barriers and the promoted diffusion of Li+ can accelerate redox kinetics. Electrochemical tests and in situ Raman results confirm the advantages of phosphorus vacancies. The S/CNT‐CoP‐Vp electrode presents outstanding cycling performance and achieves a high capacity of 8.03 mAh cm−2 under lean electrolyte condition (E/S = 5 μLE mg−1S). This work provides a new insight into improving the performance of Li–S batteries through defect engineering. [ABSTRACT FROM AUTHOR]

Aqueous zinc batteries (ZBs) have flourished due to their advantages of low‐cost and intrinsically safe water‐based electrolytes. However, in the traditional liquid electrolyte, sufficient energy density and efficiency for practical utility have not been realized yet. Here, instead of the use of a strong acid/alkali pH environment to elevate the working voltage in an aqueous solution, an ion concentration/dilution strategy is proposed to trigger the extra deposition/dissolution capacity of the Mn4+/Mn2+ redox reaction in normal Zn/MnO2 batteries. With the precipitation and release of Zn2+ ions during the discharge/charge process, the adjustment of manganese concentration is successfully realized via the reciprocal Zn/Mn ionic exchange rendered by the bentonite colloidal (Ben‐colloid) electrolyte. This electrolyte also triggers a self‐dissolution/deposition reaction even in the cathode‐free system. Consequently, the Zn/MnO2 battery with Ben‐colloid electrolyte affords up to 1.7× capacity release (480.7 mAh g–1) on average compared with a liquid electrolyte at 0.2 A g–1, higher capacity retention (94.3% vs 63.6%) after 500 cycles at 1 A g–1, and good elevated‐temperature endurability (up to 80 °C). This work opens up a new horizon to improve the energy density of water‐based metal ion batteries by the use of a functional electrolyte. [ABSTRACT FROM AUTHOR]

Sodium-ion batteries are considered alternatives to lithium-ion batteries for energy storage devices due to their competitive cost and source abundance. However, the development of electrode materials with long-term stability and high capacity remains a great challenge. Here, this paper describes for the first time the synthesis of a new class of core-shell MAX@K2Ti8O17 by alkaline hydrothermal reaction and hydrogenation of MAX, which grants high sodium ion-intercalation pseudocapacitance. This composite electrode displays extraordinary reversible capacities of 190 mA h g−1 at 200 mA g−1 (0.9 C, theoretical value of ≈219 mA h g−1) and 150 mA h g−1 at 1000 mA g−1 (4.6 C). More importantly, a reversible capacity of 75 mA h g−1 at 10 000 mA g−1 (46 C) is retained without any apparent capacity decay even after more than 10 000 cycles. Experimental tests and first-principle calculations confirm that the increase in Ti3+ on the surface layers of MAX@K2Ti8O17 by hydrogenation increases its conductivity in addition to enhancing the sodium-ion intercalation pseudocapacitive process. Furthermore, the distorted dodecahedrons between Ti and O layers not only provide abundant sites for sodium-ion accommodation but also act as wide tunnels for sodium-ion transport. [ABSTRACT FROM AUTHOR]