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Rational design of molecular structures is one of the effective strategies to obtain high‐performance organic cathode materials. However, besides the optimization of single‐molecule structures, the influence of the “weak” interaction forces (e.g. hydrogen bonds) in organic cathode materials on the performance of batteries should be fully considered. Herein, three organic small molecules with different numbers of hydroxyl groups (namely nitrogen heterocyclic tetraketone (DAB), monohydroxyl nitrogen heterocyclic dione (HDA), dihydroxyl nitrogen heterocyclic dione (DHT)) were selected as the cathodes of aqueous zinc ion batteries (AZIBs), and the effect of the intermolecular hydrogen bonds on their electrochemical performance was studied for the first time. Clearly, the stable hydrogen‐bond networks built through the hydroxyl groups significantly enhance the cycle stability of organic small‐molecule cathodes and facilitate rapid proton conduction between the hydrogen‐bond networks through the Grotthuss mechanism, thereby endowing them with excellent rate performance. In addition, a larger and more dense two‐dimensional hydrogen‐bond network can be constructed through multiple hydroxyl groups, further enhancing the structural stability of organic small‐molecule cathodes, giving them better cycle tolerance, excellent rate performance, and extreme environmental tolerance. [ABSTRACT FROM AUTHOR]

The evolution of inorganic solid electrolytes has revolutionized the field of sustainable organic cathode materials, particularly by addressing the dissolution problems in traditional liquid electrolytes. However, current sulfide‐based all‐solid‐state lithium‐organic batteries still face challenges such as high working temperatures, high costs, and low voltages. Here, we design an all‐solid‐state lithium battery based on a cost‐effective organic cathode material phenanthrenequinone (PQ) and a halide solid electrolyte Li2ZrCl6. Thanks to the good compatibility between PQ and Li2ZrCl6, the PQ cathode achieved a high specific capacity of 248 mAh g−1 (96 % of the theoretical capacity), a high average discharge voltage of 2.74 V (vs. Li+/Li), and a good capacity retention of 95 % after 100 cycles at room temperature (25 °C). Furthermore, the interactions between the high‐voltage carbonyl PQ cathode and both sulfide and halide solid electrolytes, as well as the redox mechanism of the PQ cathode in all‐solid‐state batteries, were carefully studied by a variety of advanced characterizations. We believe such a design and the corresponding investigations into the underlying chemistry give insights for the further development of practical all‐solid‐state lithium‐organic batteries. [ABSTRACT FROM AUTHOR]

Organic electrode materials are gaining increased attention in energy storage applications, but often encounter challenges such as low capacity and poor cycling stability. This paper explores the utilization of a 1‐D coordination polymer, copper(II)‐2,5‐dihydroxy‐1,4‐benzoquinone (Cu‐DHBQ), as a cathode material for Li‐ion batteries for the first time. Cu‐DHBQ is air‐stable, devoid of coordinated water molecules, and possesses a high theoretical capacity of 266 mAh g−1. With an optimal sodium alginate (SA) binder content of 25 wt%, the Cu‐DHBQ cathode demonstrates a notable initial capacity of 214 mAh g−1 and outstanding cycling stability, retaining 210 mAh g−1 (98% capacity retention) after 200 cycles at a current rate of 100 mA g−1. A comprehensive investigation into the capacity fading mechanisms, the bonding capability of the SA binder, and the interactions between Cu‐DHBQ and SA is conducted using scanning electron microscope (SEM), peel tests, and Fourier transform infrared spectroscopy (FTIR), respectively. Additionally, the electrochemical reaction mechanisms of Cu‐DHBQ are examined using ex situ X‐ray photoelectron spectroscopy (XPS) and FTIR. These findings offer valuable insights into understanding the electrochemical properties of coordination polymers and metal‐organic frameworks based on DHBQ, shedding light on their potential as materials for battery electrodes. [ABSTRACT FROM AUTHOR]

New promising organic electrode materials based on carbonyl-containing molecules for lithium power sources with high theoretical specific capacities of 500 mA h/g and higher are proposed. They have a molecular weight of more than 400 and a flat structure, which should ensure their practical insolubility in electrolytes. In the case of nitrogen-containing molecules, the specific stored energy exceeds 2.6 eV per interstitial lithium atom. Redox-active bridging molecules have also been proposed for organometallic framework structures, which, due to their porous structure, are potentially capable of fast charge-discharge processes. [ABSTRACT FROM AUTHOR]

Anion-hosting cathodes capable of reversibly storing large-size anions play a leading role in dual-ion batteries (DIBs). The purpose of the present review is to summarize the most promising anion-hosting cathodes for current and late-stage DIBs. This review first summarizes the developments in conventional graphite cathodes, especially the latest advances in the graphite-related research. Next, organic cathodes for the anion storage are discussed, including aromatic amine polymers, heterocyclic polymers, bipolar compounds, and all-carbon-unsaturated compounds. Then, the review focuses on the conversion-type cathodes with high theoretical specific capacities. Finally, the future research directions of the cathodes of DIBs are proposed. [ABSTRACT FROM AUTHOR]

In the emerging aqueous zinc ion batteries (AZIBs), proton (H+) with the smallest molar mass and fast (de)coordination kinetics is considered as the most ideal charge carrier compared with Zn2+ counterpart, however, searching for new hosting materials for H+ storage is still at its infancy. Herein, redox‐active hydrogen‐bonded organic frameworks (HOFs) assembled from diaminotriazine moiety decorated hexaazatrinnphthalene (HOF‐HATN) are for the first time developed as the stable cathode hosting material for boosting H+ storage in AZIBs. The unique integration of hydrogen‐bonding networks and strong π‐π stacking endow it rapid Grotthuss proton conduction, stable supramolecular structure and inclined H+ storage. As a consequence, HOF‐HATN displays a high capacity (320 mAh g−1 at 0.05 A g−1) and robust cyclability of (>10000 cycles at 5 A g−1) based on three‐step cation coordination storage. These findings get insight into the proton transport and storage behavior in HOFs and provide the molecular engineering strategy for constructing well‐defined cathode hosting materials for rechargeable aqueous batteries. [ABSTRACT FROM AUTHOR]

Emerging energy storage systems have received significant attention along with the development of renewable energy, thereby creating a green energy platform for humans. Lithium-ion batteries (LIBs) are commonly used, such as in smartphones, tablets, earphones, and electric vehicles. However, lithium has certain limitations including safety, cost-effectiveness, and environmental issues. Sodium is believed to be an ideal replacement for lithium owing to its infinite abundance, safety, low cost, environmental friendliness, and energy storage behavior similar to that of lithium. Inhered in the achievement in the development of LIBs, sodium-ion batteries (SIBs) have rapidly evolved to be commercialized. Among the cathode, anode, and electrolyte, the cathode remains a significant challenge for achieving a stable, high-rate, and high-capacity device. In this review, recent advances in the development and optimization of cathode materials, including inorganic, organometallic, and organic materials, are discussed for SIBs. In addition, the challenges and strategies for enhancing the stability and performance of SIBs are highlighted. [ABSTRACT FROM AUTHOR]

Aqueous zinc ion batteries (AZIBs) are gaining popularity as advanced energy storage devices that are economical, safe, and use resource‐abundant storage options. In this study, we have synthesized a bipolar phenothiazine organic scaffold known as 3,7‐bis(melaminyl)phenothiazin‐5‐ium iodide (PTDM), which is obtained by undergoing nucleophilic substitution through phenothiazinium tetraiodide hydrate (PTD) and melamine. Electrochemical results indicate that PTDM can act as a high‐potential cathode material for rechargeable AZIBs. In detail, the aqueous PTDM//Zn full cell exhibits a high average voltage of approximate 1.13 V, along with a specific capacity of 118.3 mAh g−1 at 0.1 A g−1. Furthermore, this demonstrated cell displays moderate long‐term cycling stability over 6400 cycles, which is encouraging and suggests potential for developing advanced organic electrode materials for rechargeable AZIBs. [ABSTRACT FROM AUTHOR]

The organic‐carbon core‐shell structure is constructed for the cathode material of [N,N'‐bis(2‐anthraquinone)]‐perylene‐3,4,9,10‐tetracarboxydiimide (PTCDI‐DAQ, 200 mAh g−1) through an interesting strategy called the surface self‐carbonization. As expected, the organic‐carbon core–shell structure (PTCDI‐DAQ@C) can endow PTCDI‐DAQ the outstanding cathode performance in Na‐ion batteries. In half cells using 1 m NaPF6/DME, PTCDI‐DAQ@C can maintain 173 mAh g−1 for nearly one year, while PTCDI‐DAQ quickly decreases from 203 to 121 mAh g−1 only after 100 cycles. Meanwhile, the constructed Na‐ion full cells with the Na‐intercalated hard carbon anode can deliver the peak discharge capacity of 195 mAh g−1cathode and the high median voltage of 1.7 V in 0.9–3.2 V, corresponding to the peak energy densities of 332 Wh kg−1cathode and 184 Wh kg−1total mass, respectively. Notably, the electrode materials only include the very cheap elements of C, H, O, N, and Na. Furthermore, the Na‐ion full cells can also show the very impressive high‐temperature (197 mAh g−1cathode at 50 °C) and subzero (185/90 mAh g−1cathode at −10/−40 °C) performances, respectively. To the best of the authors' knowledge, the comprehensive properties of the Na‐ion full cells are the best results based on organic cathodes. [ABSTRACT FROM AUTHOR]

Despite their safe and cost‐effective merits, the cycling durability of aqueous zinc–organic batteries is hindered by cathode dissolution and low coulombic efficiency of Zn metal anodes. Herein, a Zn metal‐free all‐organic zinc‐ion battery (ZIB) is proposed by using quinoxalino[2,3‐i]diquinoxalino[2′,3′:6,7]quinoxalino[2,3‐a:2,3‐c] phenazine (QDPA) cathode coupled with a 1,4,5,8‐Naphthalenetetracarboxylic diimide (NPI) anode, rendering excellent electrochemical reversibility with high utilization. Based on the molecular architecture strategy, a QDPA cathode with an enlarged aromatic ring system is designed and synthesized, which not only effectively inhibits structural collapse during cycling but also enhances the working voltage without lowering the active group ratio. Moreover, theoretical calculations and experimental results confirm the rapid H+ storage mechanism in the CN active sites of QDPA, affording ultra‐fast electrochemical kinetics. Thus, it delivers a negligible capacity decay of 0.002% up to 13 000 cycles at 20 A g−1. Moreover, the QDPA//NPI all‐organic aqueous ZIB with a high energy density of 43.1 Wh kg−1 is demonstrated to be easily disassembled and recycled by the incineration treatment after battery failure, ensuring outstanding environmental sustainability. [ABSTRACT FROM AUTHOR]

Recently, organic cathodes have received wide attention as eco‐friendly and sustainable materials for aqueous Zn‐organic batteries. However, the low voltage limits its further development and the related optimization strategies are rarely reported. Herein, three HATN‐based cathode materials containing cyano groups (named O3CN, P3CN, and P6CN) are proposed to reveal the role of cyano groups. The number of cyano groups was positively correlated with the potential, and the position of cyano groups would affect the ion mobility through the steric effect. Furthermore, the cyano group also reduces the solubility of the materials in water, greatly improving the cycle stability under low current density. As a result, the average voltage increased from 0.48 V for HATN to 0.73 V for P6CN, and the capacity retained 88.2 % after 5000 cycles at 5 A g−1. This study provides a systematic reference for the improvement of the voltage of organic cathode materials in the future. [ABSTRACT FROM AUTHOR]

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Quasi‐solid‐state lithium‐organic batteries have attracted widespread attention in view of their high safety, good mechanical strength, compromise ionic conductivity, and environmental friendliness. However, most organic electrode materials suffer from the undesirable interfacial compatibility, thus causing poor cycling stability. Herein, a quinone‐fused aza‐phenazine (THQAP) is reported with multi‐active site and compatible groups as the cathode material for constructing poly(vinylidene fluoride hexafluoro propylene) (PVDF‐HFP)‐based quasi‐solid‐state lithium‐organic batteries. Benefitting from the high compatibility between cathode material (THQAP) and gel polymer electrolytes (PVDF‐HFP), the dissolution and shuttle reaction of THQAP with hydroxyl groups are suppressed compared with its counterparts (QAP) without hydroxyl groups. As a result, THQAP in quasi‐solid‐state lithium‐organic batteries not only delivers excellent reversible capacity of 240 mAh g−1 at 50 mA g−1, but also exhibits stable cyclability with capacity retention of 78% (160 mAh g−1) after 200 cycles at 200 mA g−1. This study offers a promising strategy to develop quasi‐solid‐state lithium‐organic batteries with higher capacity and cycling stability. [ABSTRACT FROM AUTHOR]

Organic cathode materials for lithium‐ion batteries (LIBs) have elicited interest due to their wide‐ranging structures and finely regulated molecular levels. However, designing a cathode material with a high specific capacity, high rate‐performance, and long‐cycle life remains highly challenging. Herein, a nitrogenized 2D covalent organic framework (COF) with maximal active and minimal inactive groups is described and created by utilizing a coating material for single crystal LiNi0.78Mn0.12Co0.1O2 (SCNMC) cathodes for LIBs. The composite cathode delivers a high reversible capacity of 160.5 mAh g−1 at 1 C with a retention rate of 87.5% after 200 cycles. The cycled SCNMC@COF particles show no lattice gliding and micro‐cracks, demonstrating that the SC shape may considerably reduce anisotropic micro‐strain. This efficient, repeatable, and customizable method for producing SCNMC cathodes shall hasten their commercialization. The solid framework further ensures outstanding capacity retention and rate performance. According to density functional theory calculations, optimizing the loading of redox‐active groups in a stable network structure is an efficient technique for designing a stable structure and improving the cycling life of SCNCM cathode material. [ABSTRACT FROM AUTHOR]

Aqueous zinc‐ion batteries (ZIBs) are promising for next‐generation energy storage. However, the reported electrode materials for ZIBs are facing shortcomings including low capacity and unsatisfactory cycling stability etc. Herein, hexaazatrinaphthalene‐quione (HATNQ) is reported for aqueous ZIBs. The HATNQ electrodes delivered an ultrahigh capacity (482.5 mAh g−1 at 0.2 A g−1) and outstanding cyclability of >10 000 cycles at 5 A g−1. The capacity sets a new record for organic cathodes in aqueous ZIBs. The high performances are ascribed to the rich C=O and C=N groups that endowed HATNQ with a 2D layered supramolecular structure by multiple hydrogen bonds in plane with π–π interactions out‐of‐plane, leading to enhanced charge transfer, insolubility, and rapid ion transport for fast‐charge and ‐discharge batteries. Moreover, the 2D supramolecular structure boosted the storage of Zn2+/H+, particularly the storage of Zn2+, due to the more favorable O⋅⋅⋅Zn⋅⋅⋅N coordination in HATNQ. [ABSTRACT FROM AUTHOR]

Organic electrode materials have exhibited good electrochemical performance in batteries, but their voltages and rate capabilities still require improvement to meet the increasing demand for batteries with high energy and power density. Herein, we design and synthesize a branched dihydrophenazine-based polymer (p-TPPZ) as a cathode material for dual-ion batteries (DIBs) through delicate molecular design. Compared with the linear dihydrophenazine-based polymer (p-DPPZ, with a theoretical capacity of 209 mAh g–1), p-TPPZ possessed a higher theoretical capacity of 233 mAh g–1 and lower highest occupied molecular orbital energy levels,which resulted in a high actual capacity (169.3 mAh g–1 at 0.5 C), an average discharge voltage of 3.65 V (vs. Li+/Li) and a high energy density (618.2 Wh kg–1, based on the cathode materials). The branched structure of p-TPPZ led to a larger specific surface area than that of p-DPPZ, which was beneficial for the electrolyte infiltration and fast ionic transport, contributing to the high power density. Due to the fast reaction kinetics, even at a power density of 23,725 W kg–1 (40 C), the energy density still reached 474.5 Wh kg–1. We also made a detailed investigation of the p-TPPZ cathode's charge storage mechanism. This work will stimulate the further molecular design to develop organic batteries with both high energy and power density.

Redox‐active organic materials, as a new generation of sustainable resources, are receiving increasing attention in zinc‐ion batteries (ZIBs) due to their resource abundance and tunable structure. However, organic molecules with high potential are rare, and the voltage of most reported organic cathode‐based ZIBs is less than 1.2 V. Herein, we explored the redox process of p‐type organics and figured out the relationship between energy change and voltage output during the process. Then, we proposed a dual‐step strategy to effectively tune the energy change and eventually improve the output voltage of the organic electrode. Combining the regulation of the electron cloud of organic molecules and the manipulation of the solvation structure, the output voltage of an organosulfur compound based ZIB was greatly increased from 0.8 V to 1.7 V. Our results put forward a specific pathway to improve the working voltage and lay the foundation for the practical application of organic electrodes. [ABSTRACT FROM AUTHOR]

In this work, we designed and synthesized three novel polymeric cathode materials based on azo and carbonyl groups for Na‐ion and K‐ion batteries. The electrochemical performance of the polymer with a naphthalene backbone structure is better than that with benzene and biphenyl structures due to faster kinetics and lower solubility in the electrolyte. It unravels the rational design principle of extending π‐conjugation aromatic structures in redox‐active polymers to enhance the electrochemical performance. To further optimize the polymeric cathodes, the polymer with a naphthalene backbone structure is mixed with nitrogen‐doped graphene to increase the conductivity and mitigate the dissolution. The resulting cathodes deliver high specific capacity, long cycle life, and fast‐charging capability. Post‐cycling characterizations were employed to study the chemical structure and morphology evolution upon cycling, demonstrating that the active centers (azo and carbonyl groups) in the polymer can undergo reversible redox reactions with Na+/K+ for sustainable alkali‐ion batteries. [ABSTRACT FROM AUTHOR]

Potassium metal batteries (PMBs) are a compelling technology for large‐scale energy storage due to the abundance of potassium resources and high energy density. A vital obstacle to construct high‐performance PMBs is developing superior cathode materials. Tannin, a plant polyphenol, holding many active sites for redox reactions, is an auspicious high‐capacity cathode. However, the relatively poor conductivity and slight solubility in electrolyte deteriorate its capacity and cycle stability. Herein, the tannin is activated through a crosslinking reaction with polyaniline to obtain a composite cathode (i.e., ATN). It exhibits a high initial capacity of 172 mAh g−1 at 50 mA g−1, based on the electrochemical reaction mechanisms of embedding/releasing of K+ on CO and PF6− on NH. Moreover, to improve the cycling performance, a graphene oxide modified separator is developed to effectively retard the ATN shuttle. As a result, the capacity retention is significantly enhanced, for example, 82% over 300 cycles at 50 mA g−1. From a practical aspect, a full PMB of K@KxPy||ATN is built up, displaying high energy/power density and superior cycling stability, which is a step forward in the development of PMBs. [ABSTRACT FROM AUTHOR]

Organic cathode materials are plagued by their low cycle stability and poor electronic conductivity, even though they have attracted increasing attention in the context of lithium‐ion batteries (LIBs). Herein, a coordination polymer cobalt‐hexaazatriphenylene hexacarbonitrile (Co(HAT‐CN)) is prepared via a facile solvothermal method, which is composed of the redox‐active HAT‐CN linker and the Co(II) ion center. The fabricated material shows excellent structural stability and high conductivity. Moreover, graphene oxide (GO) is introduced as a substrate, and in‐situ loading of Co(HAT‐CN) on its surface shows enhanced cycling stability. For Co(HAT‐CN)/GO, a high specific capacity of 204 mAh g–1 can be retained even after 200 cycles at a current density of 40 mA g–1 in a voltage window of 1.2–3.9 V. Ex situ and in situ analyses are applied to probe the reversibility of the pyrazine redox‐active center during the cycling process and the lithium storage process. Density functional theory calculations reveal that the high conductivity of Co(HAT‐CN) should be ascribed to the narrow LUMO‐HOMO gap (0.61 eV), and strong binding of lithiated molecules. [ABSTRACT FROM AUTHOR]

Sulfide solid electrolytes with high conductivity that is close to that of liquid electrolyte have been considered to be one of the most promising electrolytes for all‐solid‐state lithium batteries (ASSLBs). Unfortunately, the narrow electrochemical windows of sulfide electrolyte and contact loss at the interface upon cycles much limits the application of sulfide‐based ASSLBs. In this work, an organic quinone cathode, 5,7,12,14‐pentacenetetrone (PT), is used to fabricate an ASSLB with a sulfide electrolyte of glass ceramic 70Li2S‐30P2S5 (LPS). Based on the various in situ/ex situ analyses, it is successfully demonstrated that the decomposition of LPS is negligible and the corresponding effects on interfacial impedance are reversible with optimized carbon additives. In addition, the inherent low Young's modulus of the PT electrode efficiently prevents the contact loss at the interface. As a result, the PT‐based ASSLBs deliver a high specific capacity (312 mAh g−1) and an excellent capacity retention (90.6%) over 500 cycles which is superior to previous reports. Moreover, a carbon‐free ASSLB is constructed by employing Mo6S8 as conductive additives in a PT‐based cathode, which shows an improved rate performance and a long life. [ABSTRACT FROM AUTHOR]

Recent studies have demonstrated that dihydrophenazine (Pz) with high redox‐reversibility and high theoretical capacity is an attractive building block to construct p‐type polymer cathodes for dual‐ion batteries. However, most reported Pz‐based polymer cathodes to date still suffer from low redox activity, slow kinetics, and short cycling life. Herein, a donor–acceptor (D–A) Pz‐based conjugated microporous polymer (TzPz) cathode is constructed by integrating the electron‐donating Pz unit and the electron‐withdrawing 2,4,6‐triphenyl‐1,3,5‐triazine (Tz) unit into a polymer chain. The D–A type structure enhances the polymer conjugation degree and decreases the band gap of TzPz, facilitating electron transportation along the polymer skeletons. Therefore the TzPz cathode for dual‐ion battery shows a high reversible capacity of 192 mAh g−1 at 0.2 A g−1 with excellent rate performance (108 mAh g−1 at 30 A g−1), which is much higher than that of its counterpart polymer BzPz produced from 1,3,5‐triphenylbenzene (Bz) and Pz (148 and 44 mAh g−1 at 0.2 and 10 A g−1, respectively). More importantly, the TzPz cathode also shows a long and stable cyclability of more than 10 000 cycles. These results demonstrate that the D–A structural design is an efficient strategy for developing high‐performance polymer cathodes for dual‐ion batteries. [ABSTRACT FROM AUTHOR]

Sodium 9,10-anthraquinone-2,6-disulfonate (Na 2 AQ26DS, 130 mAh g−1) with polyanionic character and two O–Na ionic bonds is used as an organic cathode for Li-ion batteries. Na 2 AQ26DS exhibits highly impressive cycle stability in ether electrolytes due to its polyanionic character and the effective suppression of solvent-molecule co-intercalation. In half cells (1–3.9 V vs. Li+/Li) using 1 M bis(trifluoromethanesulphonyl)imide lithium salt (LiTFSI) in 1,3-dioxolane/dimethoxyethane (DOL/DME), Na 2 AQ26DS delivers a highly stable specific capacity of 123 mAh g−1 at 50 mA g−1 for 900 cycles (6-month test) and realizes ∼69 mAh g−1 for 2800 cycles at 500 mA g−1. In the full cells with the reduced state (Li 4 TP) of lithium terephthalate (Li 2 TP) as the organic anode, the resulting Li 4 TP II Na 2 AQ26DS organic lithium-ion batteries (OLIBs) can display a highly stable average discharge capacity of 120 mAh g−1 cathode for 100 cycles at 50 mA g−1 and ∼63 mAh g−1 cathode for 1200 cycles at 500 mA g−1 in 0.2–3.3 V. A polyanionic organic cathode of sodium 9,10-anthraquinone-2,6-disulfonate (Na 2 AQ26DS, 130 mAh g−1) is reported for pure-organic Li-ion batteries. [Display omitted] • Polyanionic Na 2 AQ26DS is a new organic cathode for Li-ion batteries. • Na 2 AQ26DS delivers high stability in the ether electrolytes for 6 months. • Na 2 AQ26DS delivers a reversible capacity of 138 mAh g−1 in half cells. • Organic Li-ion batteries are built using lithium terephthalate anode. • Na 2 AQ26DS delivers an average capacity of 120 mAh g−1 in full cells. [ABSTRACT FROM AUTHOR]

Organic cathode materials have gained substantial attention in sodium‐ion batteries (SIBs) because of their low cost, structure versatility, and environmental friendliness. Nevertheless, the use of organic materials is plagued by the unsatisfactory cycling performance caused by dissolution of organic electrode materials, use of inappropriate electrolytes, and/or poor interfacial compatibility. In this work, an ultralong cycle life of SIBs through coupling an insoluble organic cathode, N, N′‐bis(glycinyl) naphthalene diimide, with ether‐based electrolytes, is realized. A thin and stable inorganic‐rich solid electrolyte interphase is constructed through a prior reduction of salt in the organic solvents in the ether‐based electrolytes, promising fast charge transfer kinetics and stable cycling performance of organic electrodes in SIBs. A superb long cycle life of 70 000 cycles at 10C is demonstrated, which is a new record for organic cathode materials in SIBs. The findings highlight the key role of electrolytes and electrolyte/electrode interfaces in furthering the practical prospects of organic electrodes. [ABSTRACT FROM AUTHOR]

Owing to undesired Zn corrosion and the formation of Zn dendrites in aqueous electrolytes, most of the examples of aqueous Zn batteries with reported excellent performance are achieved with low Zn‐utilization (<0.6 %) in the anode and low mass‐loading (<3 mg cm−2) in the cathode. Herein, we propose a new organic electrolyte for Zn batteries, which contains a zinc trifluoromethanesulfonate (Zn‐TFMS) salt and a mixed solvent consisting of propylene carbonate (PC) and triethyl phosphate (TEP). We demonstrate that this electrolyte with an optimized PC/TEP ratio not only exhibits high ionic conductivity and a wide stable potential window, but also facilitates dendrite‐free Zn plating/stripping. In particular, the TEP solvent makes the electrolyte nonflammable. Finally, a 2 V Zn//polytriphenylamine composite (PTPAn) battery is fabricated with the optimized electrolyte; it shows a high rate and a long lifetime (2400 cycles) even with a high mass‐loading (16 mg cm−2) of PTPAn in the cathode and with a high Zn‐utilization (3.5 %). [ABSTRACT FROM AUTHOR]

Aqueous zinc‐ion batteries (ZIBs) are a promising candidate for fast‐charging energy‐storage systems due to its attractive ionic conductivity of water‐based electrolyte, high theoretical energy density, and low cost. Current strategies toward high‐rate ZIBs mainly focus on the improvement of ionic or electron conductivity within cathodes. However, enhancing intrinsic electrochemical reaction kinetics of active materials to achieve fast Zn2+ storage has been greatly omitted. Herein, for the first time, stable radical intermediate generation is demonstrated in a typical organic electrode material (methylene blue [MB]), which effectively decreases the reaction energy barrier and enhances the intrinsic kinetics of MB cathode, enabling ultrafast Zn2+ storage. Meanwhile, anionic co‐intercalation essentially avoids MB molecules rearranging their configuration and sharing Zn2+ with adjacent functional groups, thus keeps the structure stable. As a result, Zn–MB batteries exhibit an excellent rate capability up to 500C and ultralong life of 20 000 cycles with a negligible 0.07% capacity decay per cycle at 100C, which is superior to that of most reported aqueous ZIBs batteries. This work provides a novel strategy of stable radical chemistry for ultrafast‐charging aqueous ZIBs, which can be introduced to other appropriate organic materials and multivalent ion battery systems. [ABSTRACT FROM AUTHOR]

Redox-active organic compounds gather significant attention for their potential application as electrodes in alkali ion batteries, owing to the structural versatility, environmental friendliness, and cost-effectiveness. However, their practical applications of such compounds are impeded by insufficient active sites with limited capacity, dissolution in electrolytes, and sluggish kinetics. To address these issues, a naphthol group-containing triarylamine polymer, namely poly[6,6'-(phenylazanediyl)bis(naphthol)] (poly(DNap-OH)) is rationally designed and synthesized, via oxidative coupling polymerization. It is capable of endowing favorable steric structures that facilitate fast ion diffusion, excellent chemical stability in organic electrolytes, and additional redox-active sites that enable a bipolar redox reaction. By exploiting these advantages, poly(DNap-OH) cathodes demonstrate remarkable cycling stability in both lithium-ion batteries (LIBs) and potassium-ion batteries (PIBs), showcasing enhanced specific capacity and redox reaction kinetics in comparison to the conventional poly(4-methyltriphenylamine) cathodes. Overall, this work offers insights into molecular design strategies for the development of high-performance organic cathodes in alkali-ion batteries., (© 2024 Wiley‐VCH GmbH.)

The emergence of solid-state battery technology presents a potential solution to the dissolution challenges of high-capacity small molecule quinone redox systems. Nonetheless, the successful integration of argyrodite-type Li 6 PS 5 Cl, the most promising solid-state electrolyte system, and quinone redox systems remains elusive due to their inherent reactivity. Here, a library of quinone derivatives is selected as model electrode materials to ascertain the critical descriptors governing the (electro)chemical compatibility and subsequently the performances of Li 6 PS 5 Cl-based solid-state organic lithium metal batteries (LMBs). Compatibility is attained if the lowest unoccupied molecular orbital level of the quinone derivative is sufficiently higher than the highest occupied molecular orbital level of Li 6 PS 5 Cl. The energy difference is demonstrated to be critical in ensuring chemical compatibility during composite electrode preparation and enable high-efficiency operation of solid-state organic LMBs. Considering these findings, a general principle is proposed for the selection of quinone derivatives to be integrated with Li 6 PS 5 Cl, and two solid-state organic LMBs, based on 2,5-diamino-1,4-benzoquinone and 2,3,5,6-tetraamino-1,4-benzoquinone, are successfully developed and tested for the first time. Validating critical factors for the design of organic battery electrode materials is expected to pave the way for advancing the development of high-efficiency and long cycle life solid-state organic batteries based on sulfides electrolytes., (© 2024 The Author(s). Advanced Materials published by Wiley‐VCH GmbH.)

Organic electrode materials are extensively applied for alkali metal (lithium, sodium, and potassium)‐ion batteries (LIBs, SIBs, and PIBs) due to their sustainability and low cost. As a typical organic cathode, poly(2,6‐anthraquinonyl sulfide) (PAQS) shows high theoretical capacity, yet its electrochemical behavior and mechanisms in alkali‐metal‐ion batteries still require clarification. Herein, PAQS microspheres are synthesized and applied as cathodes for LIBs, SIBs, and PIBs. When using traditional low‐concentration electrolytes, the reduction voltage and the initial discharge capacity of PAQS electrode in LIB, SIBs, PIBs are 2.11 V/103 mAh g−1, 1.76/1.30 V/134 mAh g−1, 1.94/1.54 V/198 mAh g−1 at 100 mA g−1, respectively, while the cycling stability of PAQS is in the order of LIBs > SIBs > PIBs. To further promote the practical application of PIBs, a facile method is demonstrated to improve the cycle stability of PAQS for PIBs by using a novel high‐concentration electrolyte. The cycling stability of PIBs with PAQS can be improved significantly to 1200 cycles with a capacity decay of 0.031% per cycle. This work may provide guidelines for developing innovative organic materials used in applicable metal‐ion batteries demonstrates the impact of electrolyte optimization on improving the cycling stability. [ABSTRACT FROM AUTHOR]

Aluminum 3D thin film anodes fully integrated with a separator are fabricated by sputtering and enable rechargeable aluminum metal batteries with high power performance. The 3D thin film anodes have an approximately four to eight times larger active surface area than a metal foil, which significantly both reduces the electrochemical overpotential, and improves materials utilization. In full cells with organic cathodes, that is, aluminum metal–organic batteries, the 3D thin film anodes provide 165 mAh g−1 at 0.5 C rate, with a capacity retention of 81% at 20 C, and 86% after 500 cycles. Post‐mortem analysis reveals structural degradation to limit the long‐term stability at high rates. As the multivalent charge carrier active here is AlCl2+, the realistic maximal specific energy, and power densities at cell level are ≈100 Wh kg−1 and ≈3100 W kg−1, respectively, which is significantly higher than the state‐of‐the‐art for Al batteries. [ABSTRACT FROM AUTHOR]

Organic cathode materials have attracted extensive attention because of their diverse structures, facile synthesis, and environmental friendliness. However, they often suffer from insufficient cycling stability caused by the dissolution problem, poor rate performance, and low voltages. An in situ electropolymerization method was developed to stabilize and enhance organic cathodes for lithium batteries. 4,4′,4′′‐Tris(carbazol‐9‐yl)‐triphenylamine (TCTA) was employed because carbazole groups can be polymerized under an electric field and they may serve as high‐voltage redox‐active centers. The electropolymerized TCTA electrodes demonstrated excellent electrochemical performance with a high discharge voltage of 3.95 V, ultrafast rate capability of 20 A g−1, and a long cycle life of 5000 cycles. Our findings provide a new strategy to address the dissolution issue and they explore the molecular design of organic electrode materials for use in rechargeable batteries. [ABSTRACT FROM AUTHOR]

Several forms of organic materials have arisen as promising candidates for future active electrode materials for Li‐ion and post‐Li‐ion batteries, owing to a series of key features that encompasses sustainability, accessibility, and tunable electrochemical properties by molecular modifications. In this context, a series of organic electrode materials (OEMs) are investigated to further understand their thermodynamic and electronic properties. Through an evolutionary algorithm approach combined with first‐principles calculations, the crystal structure of lithiated and delithiated phases of these OEMs and their respective NO2‐substituted analogues are predicted. This framework allows a first assessment of their electrochemical and electronic properties and further understanding on the effects of the nitro group in the substituted compounds. NO2 is found to strongly affect structural and thermodynamic aspects during the electrochemical reaction with the reducing equivalents (Li++e−), changing the OEM's character from a low‐potential anode to a high‐potential cathode by creating a localization of the additional electrons, thus resulting in a better‐defined redox‐active center and leading to a shift in the potential from 0.92 V to 2.66 V vs. Li/Li+. [ABSTRACT FROM AUTHOR]

Developing cathodes that can support high charge–discharge rates would improve the power density of lithium‐ion batteries. Herein, the development of high‐power cathodes without sacrificing energy density is reported. N,N′‐diphenylphenazine was identified as a promising charge‐storage center by electrochemical studies due to its reversible, fast electron transfer at high potentials. By incorporating the phenazine redox units in a cross‐linked network, a high‐capacity (223 mA h g−1), high‐voltage (3.45 V vs. Li/Li+) cathode material was achieved. Optimized cross‐linked materials are able to deliver reversible capacities as high as 220 mA h g−1 at 120 C with minimal degradation over 1000 cycles. The work presented herein highlights the fast ionic transport and rate capabilities of amorphous organic materials and demonstrates their potential as materials with high energy and power density for next‐generation electrical energy‐storage technologies. [ABSTRACT FROM AUTHOR]

An acidic solution based method towards flexible lithium ion battery (LIB) cathodes is developed in this work with perylene diimide (PDI) as the electroactive component and carbon cloth (CC) as the current collector. In this approach, PDI is firstly dispersed in concentrated sulfuric acid (H2SO4) and then deposited on CC substrate after the dilution of H2S04, which provides an organic solvent-free strategy to construct integrated LIB cathodes. The acdic solution based fabrication process also allows the facile adjusting of loading amounts of PDI in the cathodes, which can effectively influence the battery performances of the PDI/CC cathodes. As the result, the acidic solution processed PDI/CC cathode can deliver a high specific capacity of ~ 36mAh.g-1 at the current density of 50 m A.g-1 in both half cell with lithium foil as anode and full cell with pre-lithiated CC as anode. In both types of the batteries, the PDI/CC cathodes show good cycling stabilities by retaining ~ 84% of the initial capacities after 300 charge-discharge cycles at 500 mA.g-1. Additionally, the excellent mechanical stability of the PDI/CC cathode enables the LIBs in pouch cell to maintain the electrochemical performances under various bending states, demonstrating their potentials for flexible LIBs. [ABSTRACT FROM AUTHOR]

An organic Na‐ion battery is reported with a polyanionic 9,10‐anthraquinone‐2,6‐disulfonate (Na2AQ26DS, 130 mAh g−1) cathode and the Na‐intercalated state (Na4TP) of sodium terephthalate (Na2TP, 255 mAh g−1) as the anode. The resulting full cells deliver the maximum discharge capacity of 131 mAh g−1cathode in 0.5–3.2 V, simultaneously maintaining the average value of ≈62 mAh g−1cathode during 1200 cycles (0.5 A g−1, ≈4 C). These results are among the best performing organic sodium‐ion full cells reported to date. [ABSTRACT FROM AUTHOR]

Abstract Herein, graphite is proposed as a reliable Ca2+‐intercalation anode in tetraglyme (G4). When charged (reduced), graphite accommodates solvated Ca2+‐ions (Ca‐G4) and delivers a reversible capacity of 62 mAh g−1 that signifies the formation of a ternary intercalation compound, Ca‐G4·C72. Mass/volume changes during Ca‐G4 intercalation and the evolution of in operando X‐ray diffraction studies both suggest that Ca‐G4 intercalation results in the formation of an intermediate phase between stage‐III and stage‐II with a gallery height of 11.41 Å. Density functional theory calculations also reveal that the most stable conformation of Ca‐G4 has a planar structure with Ca2+ surrounded by G4, which eventually forms a double stack that aligns with graphene layers after intercalation. Despite large dimensional changes during charge/discharge (C/D), both rate performance and cyclic stability are excellent. Graphite retains a substantial capacity at high C/D rates (e.g., 47 mAh g−1 at 1.0 A g−1 s vs 62 mAh g−1 at 0.05 A g−1) and shows no capacity decay during as many as 2000 C/D cycles. As the first Ca2+‐shuttling calcium‐ion batteries with a graphite anode, a full‐cell is constructed by coupling with an organic cathode and its electrochemical performance is presented.

Organic electrodes that embrace multiple electron transfer and efficient redox reactions are desirable for green energy storage batteries. Here, a novel organic electrode material is synthesized, i.e., 2, 2'-((disulfanediylbis (4, 1-phenylene)) bis(azanediyl)) bis (naphthalene-1, 4-dione) (MNQ), through a simple click reaction between common carbonyl and organosulfur compounds and demonstrate its application potential as a high-performance cathode material in rechargeable lithium batteries. MNQ exhibits the aggregation effect of redox-active functional groups, the advantage of fast reaction kinetics from molecular structure evolution, and the decreased solubility in aprotic electrolytes resulting from intermolecular interactions. As expected, the MNQ electrode exhibits a high initial discharge capacity of 281.2 mA h g -1 at 0.5 C, equivalent to 97.9% of its theoretical capacity, and sustains stable long-term cycling performance of over 1000 cycles at 1 C. This work adds a new member to the family of organic electrode materials, providing performance-efficient organic molecules for the design of rechargeable battery systems, which will undoubtedly spark great interest in their applications., (© 2023 Wiley‐VCH GmbH.)

This study introduces a sustainable approach to designing organic cathode materials (OCMs) for lithium-ion batteries as a potential replacement for traditional metal-based electrodes. Utilizing green synthetic methodologies, we synthesized and characterized five distinct quinone derivatives and investigated their electrochemical attributes within Li-ion battery architectures. Notably, the observed specific capacities were lower than the theoretical predictions, suggesting limitations in achieving efficient redox reactions in a coin-cell configuration. Among the quinone derivatives studied, one variant derived from natural vanillin showed superior cycle stability, maintaining 58% capacity retention over 95 charge-discharge cycles, and achieving a Coulombic efficiency of 90%. Importantly, we discovered that the commonly used Super-P conductive carbon did not yield any measurable battery performance; instead, these quinones necessitated the incorporation of graphene nanoplatelets as the conductive matrix. Through a facile one-step synthesis in ethanol or water, we have demonstrated a viable synthetic route for producing OCMs, albeit with moderate performances, which have attempted to address common concerns of high solubility and poor redox reactivity of previous OCMs, thereby offering a sustainable pathway for the development of organic-based energy storage devices.

Potassium-ion batteries (PIBs) are gradually gaining attention owing to their natural abundance, excellent security, and high energy density. However, developing excellent organic cathode materials for PIBs to overcome the poor cycling stability and slow kinetics caused by the large radii of K + ions is challenging. This study demonstrates for the first time the application of a hexaazanonaphthalene (HATN)-based 2D π-d conjugated metal-organic framework (2D c-MOF) with dual-active centers (Cu-HATNH) and integrates Cu-HATNH with carbon nanotubes (Cu-HATNH@CNT) as the cathode material for PIBs. Owing to this systematic module integration and more exposed active sites with high utilization, Cu-HATNH@CNT exhibits a high initial capacity (317.5 mA h g -1 at 0.1 A g -1 ), excellent long-term cycling stability (capacity retention of 96.8% at 5 A g -1 after 2200 cycles), and outstanding rate capacity (147.1 mA h g -1 at 10 A g -1 ). The reaction mechanism and performance are determined by combining experimental characterization and density functional theory calculations. This contribution provides new opportunities for designing high-performance 2D c-MOF cathodes with multiple active sites for PIBs., (© 2023 Wiley-VCH GmbH.)

Abstract: A key challenge faced by organic electrodes is how to promote the redox reactions of functional groups to achieve high specific capacity and rate performance. Here, we report a two‐dimensional (2D) microporous covalent–organic framework (COF), poly(imide‐benzoquinone), via in situ polymerization on graphene (PIBN‐G) to function as a cathode material for lithium‐ion batteries (LIBs). Such a structure favors charge transfer from graphene to PIBN and full access of both electrons and Li+ ions to the abundant redox‐active carbonyl groups, which are essential for battery reactions. This enables large reversible specific capacities of 271.0 and 193.1 mAh g−1 at 0.1 and 10 C, respectively, and retention of more than 86 % after 300 cycles. The discharging/charging process successively involves 8 Li+ and 2 Li+ in the carbonyl groups of the respective imide and quinone groups. The structural merits of PIBN‐G will trigger more investigations into the designable and versatile COFs for electrochemistry. [ABSTRACT FROM AUTHOR]

Abstract: Low‐cost multivalent battery chemistries (Mg2+, Al3+) have been extensively investigated for large‐scale energy storage applications. However, their commercialization is plagued by the poor power density and cycle life of cathodes. A universal polyimides@CNT (PI@CNT) cathode is now presented that can reversibly store various cations with different valences (Li+, Mg2+, Al3+) at an extremely fast rate. The ion‐coordination charge storage mechanism of PI@CNT is systemically investigated. Full cells using PI@CNT cathodes and corresponding metal anodes exhibit long cycle life (>10000 cycles), fast kinetics (>20 C), and wide operating temperature range (−40 to 50 °C), making the low‐cost industrial polyimides universal cathodes for different multivalent metal batteries. The stable ion‐coordinated mechanism opens a new foundation for the development of high‐energy and high‐power multivalent batteries. [ABSTRACT FROM AUTHOR]

Magnesium metal is a superior anode which has double the volumetric capacity of lithium metal and has a negative reduction potential of −2.37 V vs. the standard hydrogen electrode. A major benefit of magnesium is the apparent lack of dendrite formation during charging which is one of the crucial concerns of using a lithium metal anode. In this Review, we highlight the foremost research in the development of electrolytes and cathodes and discuss some of the significant challenges which must be overcome in realizing a practical magnesium battery. [ABSTRACT FROM AUTHOR]

Despite the fascinating Li storage properties of organic carbonyl compounds, e.g., high therotical capacity and fast kinetics, it is still lack of a facile and effective way that capable of large-scale producion of advanced carbonyl cathodes for Li-ion batteries (LIBs). Here, a generic strategy is proposed by combining sonication and hydrothermal techniques for scalable synthesis of high performance organic carbonyl cathodes for LIBs. A series of commercialized vat dyes with abundant electroactive conjugated carbonyl groups are confined in between the graphene layers, forming a compatible 3D hybrid architecture. The unique structure affords good Li+ ions accessibility to the electrode and short Li+ ions diffusion length. Meanwhile, each sandwiched graphene layer functions as a miniature current collector, ensuring fast electron transport throughout the entire electrode. Consequently, the cathodic performances of LIBs using the composites as electrodes, for example, Vat Green 8/graphene, Vat Brown BR/graphene, and Vat Olive T/graphene, possess high specific capacity, exceptional cycling stability, and excellent rate capability. The effect of vat dye content on the morphology, structure, and the final electrochemical performance of the composites is investigated as well. This work provides a versatile and low-cost platform for large-scale development of advanced organic-based electrodes toward sustainable energy fields. [ABSTRACT FROM AUTHOR]

Compared to anode materials in Li-ion batteries, the research on cathode materials is far behind, and their capacities are much smaller. Thus, in order to address these issues, we believe that organic conjugated materials could be a solution. In this study, we synthesized two non-polymeric dianhydrides with large aromatic structures: NDA-4N (naphthalenetetracarboxylic dianhydride with four nitrogen atoms) and PDA-4N (perylenetetracarboxylic dianhydride with four nitrogen atoms). Their electrochemical properties have been investigated between 2.0 and 3.9 V (vs. Li+/Li). Benefiting from multi-electron reactions, NDA-4N and PDA-4N could reversibly achieve 79.7 % and 92.3 %, respectively, of their theoretical capacity. Further cycling reveals that the organic compound with a relatively larger aromatic building block could achieve a better stability, as an obvious 36.5 % improvement of the capacity retention was obtained when the backbone was switched from naphthalene to perylene. This study proposes an opportunity to attain promising small-molecule-based cathode materials through tailoring organic structures. [ABSTRACT FROM AUTHOR]

• A perylene-based imide derivative with larger π-conjugated structure (2PDI) was prepared as electrode material. • The assembled 2PDI battery offered an ultralong cycling stability with 99.4% of capacity retention after 50 000 cycles at 3000 mA g−1. • Its mechanism of reversible co-insertion Zn2+/H+ are verified via electrochemical tests and ex-suit characterizations. • The most favorable structure of discharge products was further clarified and discussed to be (2PDI) 2 (H+) 6 (Zn2+). Organic carbonyl compounds as electrode materials have exhibited promising candidates for application in next-generation aqueous rechargeable batteries. However, a primary concern that is poor cycling performance are still remains due to high solubility of discharge products, which greatly limits their broader application. Herein, we developed a strategy to enhance the cyclability of aqueous zinc-organic batteries (AZOBs) by the terminal imidization and lateral π-system extension of perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA). This strategy resulted in a perylene-based imide derivative with larger π-conjugated structure (2PDI), significantly inhibiting the solubility in an aqueous electrolyte. As expected, 2PDI as cathode offered a discharge capacity of 72.8 mA h g−1 at a current density of 100 mA g−1, and even retaining 99.4% capacity after ultralong 50 000 cycles at 3000 mA g−1. Its mechanism of reversible co-insertion Zn2+/H+ at the carbonyl site was verified via electrochemical tests and ex-suit characterizations. Moreover, density functional theory calculation (DFT) also revealed this co-insertion mechanism. [ABSTRACT FROM AUTHOR]