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With the progressively widespread application of lithium‐ion batteries, their energy density and power density are being pursued to the extremely high. However, both cannot be reached simultaneously at present. Tortuosity depicts the relationship in ionic diffusion between bulk electrolyte and the electrolyte in a porous electrode, provides information about channels within electrodes, and correlates the current dilemma between energy density and power capability of the lithium‐ion batteries. It is crucial to upgrade the fast charging and discharging performance of LIBs electrodes without losing volumetric energy density and using tortuosity as a guide is able to achieve this goal fundamentally. Meanwhile, tortuosity can serve as an evaluation parameter for production quality assessment, but this demands a fast, accurate, and cost‐effective measuring method. After the definition and measurement of tortuosity are provided, this article analyzes the structural influencing factors of tortuosity which have impacts on ion transportation and subsequently on tortuosity to facilitate a more systematic and comprehensive picture. Through the discussion of contradictions and influencing factors, a more refined transmission line model (the refined TLM) is perceived as the very first step to drive both aforementioned goals toward success and is discussed in the perspective part. [ABSTRACT FROM AUTHOR]

In this paper, a series of iron oxide/reduced graphene oxide/carbon nanotube composites (K3‐Fe2O3‐rGO/CNT) with well‐dispersedFe2O3 particles are prepared by in situ reaction and then heat‐treatment, and its electrochemical and battery performancesare studied as the anode material of lithium‐ion batteries. The results show that the introduction of reduced graphene oxide/carbon nanotube (rGO/CNT) improves the electrochemical and battery performances of the prepared electrode material. In particular, the K3‐Fe2O3‐rGO/CNT (30 %) composite material has a reversible capacity of 1559 mAh g−1 after 100 charge/discharge cycles at 100 mA g−1. And its specific discharge capacityis 641.1, 639.7, 609.5, 578.6 and 543 mAh g−1at the current density of 100, 200, 500, 1000 and 2000 mA g−1, respectively,with 84.7 % of capacity retention even with a 10 times increase in current density. The research of charge storage indicates that the electrochemical process is a mixed control process of diffusion and capacitance. The improved electrochemical and battery performancesfor the composite electrode material can be attributed to the enhanced dispersion of the Fe2O3 and the enhanced conductive network provided by rGO/CNT composite carbon. It makes a promising way to prepare high performance of anode material for lithium‐ion battery. [ABSTRACT FROM AUTHOR]

Inspired by dative boron‐nitrogen (B←N) bonds proven to be the promising dynamic linkage for the construction of crystalline covalent organic polymers/frameworks (COPs/COFs), we employed 1,4‐bis(benzodioxaborole) benzene (BACT) and N,N′‐Di(4‐pyridyl)‐1,4,5,8‐naphthalenetetracarboxdiimide (DPNTCDI) as the corresponding building blocks to construct a functional COP (named as CityU‐25), which had been employed as an anode in rechargeable lithium ion batteries. CityU‐25 displayed an excellent reversible lithium storage capability of 455 mAh/g after 170 cycles at 0.1 A/g, and an impressive one of 673 mAh/g after 720 cycles at 0.5 A/g. These findings suggest that CityU‐25 is a standout candidate for advanced battery technologies, highlighting the potential application of this type of materials. [ABSTRACT FROM AUTHOR]

Antimony（Sb） has high theoretical specific capacity and moderate reaction potential, but poor cycling stability and rate performance caused by large volume expansion and sluggish reaction kinetics limit its development in alkali‐ion batteries. The construction of carbon/Sb composites can solve this problem, but the traditional single carbon composite and poor Sb/carbon interface have limited promotion. Here, under the guidance of theoretical calculations, a strategy of hierarchical double carbon composite is proposed to enhance the performance of Sb anode, and systematically reveal the lithium/sodium ions (Li+/Na+) storage mechanism of Sb in complex composite system. Sb nanoparticles (Sb NPs) are encapsulated in carbon sphere matrix with strong interfacial chemical bond to form the first level composite material, and then the highly conductive and mechanically strong graphene is used as a three‐dimensional skeleton network to connect the first level composite to form the second level composite material. The hierarchical double carbon/Sb composite exhibits excellent rate (228 mAh g−1 @ 20 A g−1) and long cycling performance (373.7 mAh g−1 @ 2 A g−1 after 2200 cycles, capacity retention of 93.1%). This work may expand structural design and interface regulation of Sb/C composites and providing theoretical guidance for metal anodes development. [ABSTRACT FROM AUTHOR]

Addressing the oxidation state of functional materials such as transition metal oxides is a current critical challenge and requires new methodologies to characterize their electronic structure within surface to bulk resolution at the nanometer scale. One approach to this issue is the combination of co‐localized soft and hard X‐ray photoelectron spectroscopies for a non‐destructive depth profiling. In this work, we demonstrate the capability to characterize the oxidation state of cobalt in LiCoO2 thin films, a model electrode material in the Li‐ion battery field, within the first 15 nm. The capability of the methodology to address the surface evolution of the cobalt oxidation state is tested through a proof of concept surface modification introduced by Ar‐ion sputtering. To address the cobalt local electronic structure at different depths from the extreme surface, we exploited Auger‐free Hard X‐ray photoelectron spectroscopy (HAXPES) spectra to fit the Co 2p core‐level features in the X‐ray photoelectron spectroscopy (XPS) spectra. This approach may pave the way for a better understanding of the surface electronic structure changes in transition metal oxides driven by their applications in a broad range of technologies. [ABSTRACT FROM AUTHOR]

The recovery of critical metals from spent lithium‐ion batteries (LIBs) is important to sustainable development and environment protection. In this paper, sec‐octylphenoxyacetic acid (CA‐12) was first used to recover valuable metals in LIBs. The effects of phase modifier, initial feed pH, extraction kinetics and thermodynamics, CA‐12 concentration and saponification degree were studied and optimized. Under the optimal conditions, 99 % of nickel, cobalt and manganese were co‐extracted to the organic phase, and the loss of lithium was 7 %. The extracted metal ions could be stripped with 0.04 mol/L HCl equivalently. In the spent LIBs powder leaching experiment, leaching efficiencies of all components were greater than 95 %. In the impurity removal stage, extractant N902 was used to remove copper, while iron and aluminum were eliminated by hydrolysis. After two‐stage extraction, the total extraction efficiencies of nickel, cobalt and manganese reached 99.7 %, 99.4 %, 98.45 %, respectively. Finally, lithium in the raffinate was precipitated by saturated Na2CO3, the purity of recovered Li2CO3 was up to 97.7 %. After 5 times cycles, CA‐12 still maintained excellent extraction capacity, showing its potential application prospects for recovering critical metals form spent LIBs. [ABSTRACT FROM AUTHOR]

LiFePO4 is one of the most widely used cathode materials for lithium‐ion batteries, and the low‐temperature performance of LiFePO4‐based batteries has been widely studied in recent years. Herein, a 3.5 Ah pouch‐type full battery was assembled using LiFePO4 as the cathode and artificial graphite as the anode. For the LiFePO4‐based cathode, carbon‐coated aluminum foil was selected as the current collector, and a 0D–1D–2D multi‐scale conductive network was introduced into the electrode. Notably, both the carbon‐coated current collector and novel conductive network could significantly reduce the internal resistance of the LiFePO4‐based battery, thus improving its electrochemical dynamics and low‐temperature performance. This paper provides a theoretical basis for the development of low‐temperature LiFePO4‐based batteries. [ABSTRACT FROM AUTHOR]

Electromobility makes batteries with a high energy density more and more important. In this context, lithium‐sulfur batteries are among the most promising energy storage devices of the future. However, there are still numerous problems to be solved before lithium‐sulfur batteries can be put into practice. Some of these problems and the general functionality of lithium sulfur batteries can be demonstrated in model experiments. [ABSTRACT FROM AUTHOR]

As an olivine‐based cathode with high discharge platform and theoretical capacity, Li3V2(PO4)3's (LVP's) low conductivity and excessive grain size are the important factors hindering its development in the battery field. Halloysite nanotubes (HNTs) is a natural and cheap nanotube‐like material with large specific surface area and abundant surface nucleation sites, which can cooperate with conductive carbon layer to solve the deficiency of LVP. In this paper, we design a cathode material for in‐situ growth of LVP on HNTs (LVP@HNTs) and demonstrate that it has the appropriate particle size and the excellent specific surface area in the mass ratio of LVP to HNTs is 2:1. The capacity retention rate of LVP@HNTs‐2 reached almost 100% (97.0 mAh g−1) after 100 cycles at a low rate of 0.5 C. Moreover, its specific discharge capacity is 89.3 mAh g−1 at a high rate of 20 C and its capacity retention rate is as high as 90.1% (80.5 mAh g−1) after 5,000 cycles, showing that the LVP@HNTs‐2 has marvelous rate capability and cycle stability. This study provides an innovative strategy for the development of the high‐performance cathode materials with low‐cost, excellent rate capability, and cycle stability of lithium ion batteries. [ABSTRACT FROM AUTHOR]

Lignin, as the second most abundant natural polymer, has not been fully utilized in the industrial field due to the complex structure and functional groups. In this paper, polyvinyl chloride (PVC) coated lignin‐silica composites (PLS) with excellent cycling performance are prepared from rice husk and PVC through the method of alkali extraction and acid precipitation and mechanical mixing process. Due to the existence of functional groups on the surface of lignin, it can be closely combined with PVC to form a stable structure. The first discharge specific capacity and Coulombic efficiency of PLS is 1436 mA h g−1 and 56 %, respectively, and the reversible capacity is 720 mA h g−1 after 200 cycles at 0.1 A g−1, showing a stable cycling performance. This work promotes the application of lignin in the SiO2/C anode material of lithium ion battery, and confirms the stable combination between PVC and organic carbon. [ABSTRACT FROM AUTHOR]

The oxide glass‐based anodes for lithium‐ion Batteries (LiBs) still suffer from two critical drawbacks, that is, low reversible capacity and low electrical conductivity. Here, we report a new way to overcome the two drawbacks. Specifically, we chose 50Fe2O3–50P2O5 (50Fe50P) glass as the anode material for LiBs, and then thermally treat it at 1118 K (Tg+345 K) for 0.5 h under reducing atmosphere (5 mol% H2+95 mol% Ar). The thermal reduction treatment led to formation of Fe2(P4O12) and Fe2Fe5(P2O7)4 crystals. The reduced glass‐based anode for LiBs exhibits the capacity of 373 mA h g−1 after 1 000 charge/discharge cycles at 1 A g−1, which is higher than that of the oxidized one. The reduction treatment greatly lowers the charge transfer resistance in the glass anode, indicating the enhancement of the electrical conductivity. This performance improvement could arise from the increase of accessible active sites for Li+ ion storage and transfer due to the existence of crystal–crystal/crystal–glass boundaries, as well as from the improvement of the electron transfer between Fe2+ and Fe3+ during cycling. This reduction–crystallization approach could help develop high‐performance oxide glass‐ceramics based anodes for advanced LiBs. [ABSTRACT FROM AUTHOR]

As a high‐capacity anode material for lithium ion batteries, γ‐Fe2O3 is a promising alternative to conventional graphite among multifarious transition metal oxides owing to its high theoretical specific capacity (1007 mAh g−1), abundant reserves, good safety and low cost. However, improving the electrical conductivity and overcoming the morphological damage caused by the severe volume expansion during cycling are still the tricky problems to be solved. Herein, a three‐dimensional heterostructure composite (γ‐Fe2O3/PC‐rGO60) was prepared by a facile solvothermal reaction followed by heat treatment in inert atmosphere. This composite material exhibits a reversible charge specific capacity of 1035 mAh g−1 at the current density of 0.1 A g−1. After 100 cycles at 0.2 A g−1, the capacity is increased from 966.2 to 1091.1 mAh g−1. Even cycled for 200 cycles at 1 A g−1, the capacity is only decreased from 751.4 to 670.6 mAh g−1, giving capacity retention of 89.3%. The rGO network supported flexible composite architecture is beneficial for accommodating the volume expansion of the γ‐Fe2O3 active material during the lithiation/delithiation process. Besides, the conductive rGO network and the in‐situ formed pyrolytic carbon (PC) can provide a smooth electron transmission path and a favorable lithium ion transport channel. [ABSTRACT FROM AUTHOR]

In order to advance the current technology to cope with the future challenges, the search of anode materials beyond‐graphite for use in lithium ion battery is in progress. First principles calculations were conducted to investigate the prospects of SiC layers as lithium intercalation compound. In order to investigate electrolyte decomposition triggered by high lithium reactivity in Li:SiC anode the molecular dynamics computations were performed. The simulations to model the electrode‐electrolyte interface and temperature profiling were studied via reactive force field calculations that ruled out the reactivity at room temperature whereas uniform temperature afterwards sheds light on performance of the system. The diffusion coefficient of Li in layered SiC is calculated at different values of temperature. The ionic diffusion shown an activation energy of 0.046 eV whereas diffusion coefficient is found of the order 10−11 m2/s. The intercalation voltage calculated with grand canonical Monte Carlo simulation is found as 1.85 V. The ReaxFF simulations predicted that volume expansion in SiC layers appeared less than Si which shows the improved performance of the anode material. [ABSTRACT FROM AUTHOR]

The addition of 3,3,3‐trifluoropropyl acetate (TFPA) to electrolyte in a Li‐ion rechargeable battery (LIB) provides a means for increasing the discharge performance at low temperatures as a result of the formation of a superior solid electrolyte interphase (SEI) on the graphite anode. For instance, the addition of 2 wt% TFPA to the electrolyte significantly increased the cycle stability and the discharge capacities at low temperatures (‐10°C) even at current rates of 3 C. The SEI films formed on the graphite anodes were characterized by electrochemical and spectroscopic techniques and by computational analysis. Although the formation of LiF on the anode has been recognized, present research revealed that the decomposition of TFPA on the anode surface resulted in the formation of an SEI layer consisting predominantly of organic fluorides. This layer suppressed the decomposition of the electrolyte resulting in a decreased anode impedance and an increase in cycle stability and discharge capacity at low temperatures. [ABSTRACT FROM AUTHOR]

Highly concentrated electrolyte solutions have various unique characteristics for use in secondary batteries, including lithium ion batteries. The superlative performance of batteries should be achieved not at a saturating concentration, but rather at an appropriate concentration in terms of both Li+ transport in electrolyte solutions and Li+ transfer across interfaces between the electrodes and electrolyte solutions. This work focused on the latter, and studied the effect of the electrolyte concentration on interfacial Li+ transfer kinetics. Interfacial resistance between a solid electrolyte and LiBF4/PC electrolyte solutions of different concentrations were investigated by impedance spectroscopy using a four‐electrode cell, and the activation energy was evaluated by the least‐squares method. The results revealed that specific concentrations reduced interfacial resistance and activation energy. The solution structure of these electrolyte solutions was characterized by Raman spectroscopy, and was associated with the low interfacial resistance and activation energy. [ABSTRACT FROM AUTHOR]

This article provides a low cost and green environmental preparation method to produce a high performance of stannum‐carbon lithium battery anode material. The advantage of this method is not only for improving the performance and stability comparing with the stannum‐carbon lithium battery, but also show a way for the industrial scale for the applications at the same time. This paper provides a reasonably designed hybrid composite as lithium ion battery anode that shows a reversible capacity of 440 mAh g−1 after 500 cycles at 1.0 A g−1. This result is mainly attributed to the nanocrystallization of stannum and the introduction of expansion space by combination of wheat flour nature properties and redox process. [ABSTRACT FROM AUTHOR]

In recent years, with the spread of electric vehicles, improvement in the performance of lithium ion batteries has been required. Evaluation of the active material is important because the performance of the lithium ion battery is affected by the movement of lithium ions at the electrode active material-electrolyte interface. In this study, we fabricated a lithium ion battery with the sensing plate, which is a potential sensor, attached to the positive electrode, and evaluated lithium ion battery with a terahertz chemical microscope (TCM). As a result, we succeeded in measuring the potential distribution of the positive electrode during charging and discharging, and the local impedance. [ABSTRACT FROM AUTHOR]

For low‐cost positive electrode chemistry, including lithium manganese oxide (LMO) and its mixture with high capacity lithium nickel manganese cobalt oxide (NMC), such as NMC532 blended with LMO, transition metal dissolution potentially compromises battery cycle life. Here the benefits of using lithium‐ion exchanged zeolite (Li‐zeolite) are demonstrated on mitigating transitional metal dissolution and improving the cycling performance for batteries particularly at high temperature. Adopted as an additive to cathode electrodes through mixing or coating, Li‐zeolite has shown the improved cycle life. Postmortem analysis through X‐ray photoelectron spectroscopy (XPS) and electron probe micro‐analyzer (EPMA) further clarifies the functions of Li‐zeolite in batteries and advises it future development. While the efforts on further optimization of electrode quality and increasing loading for desirable energy density is ongoing, the processes and results reported in this work provide a simple and practical route to enhance the performance for LMO and LMO blended electrodes. The application of Li‐zeolite is envisioned as a low‐cost and scalable path which can be potentially implemented in electrode manufacturing. [ABSTRACT FROM AUTHOR]

ZnSe has got extensive attention for high‐performance LIBs anode due to its remarkable theoretical capacity and environmental friendliness. Nevertheless, the large volume variation for the ZnSe in the discharge/charge processes brings about rapid capacity fading and poor rate performance. Herein, ZnSe/C hollow polyhedrons are successfully synthesized by selenization of zeolitic imidazolate framework‐8 (ZIF‐8) with resorcinol‐formaldehyde (RF) coating. The protection of C layer derived from RF coating layer and Ostwald ripening during the process of selenization play important roles in promoting formation of ZnSe/C hollow polyhedrons. The ZnSe/C hollow polyhedrons exhibit good rate performance and long‐term cycle stability (345 mAh g−1 up to 1000 cycles at 1 A g−1) for lithium ion batteries (LIBs) anode. The improved electrochemical performance is benefit from the unique ZnSe/C hollow structure, in which the hollow structure can effectively avoid terrible volume expansion, and the thin ZnSe/C shell can not only provide adequate diffusion paths of lithium ions and but also enhance the electronic conductivity. [ABSTRACT FROM AUTHOR]

Magnesium borate oxide (MBO) coated lithium‐rich layered Li1.2Mn0.54Co0.13Ni0.13O2 particles are synthesized via a wet chemical coating method. The X‐ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, transmission electron microscopy, and X‐ray photoelectron spectrometer results indicate that the cathode particles are uniformly covered with a MBO layer. The results of charge/discharge tests show that the MBO‐coated electrode has enhanced electrochemical properties both in rate capability and cycling stability compared to the bare one. Specifically, 3 wt. % MBO‐coated sample has capacity retention of 98.3 %, much more than the bare one of only 79.2 % after 100 cycles at 1 C. Furthermore, the MBO‐coated electrode retains a superior high‐rate capacity of 90 mAh g−1 at 10 C. The remarkably enhanced rate capability and cycling stability of MBO‐coated electrode is ascribed to the MBO coating layer efficiently isolating the bulk Li1.2Mn0.54Co0.13Ni0.13O2 from direct contact with the electrolyte, and facilitating both charge transfer reaction and the kinetics of lithium ion diffusion through the surface layer. [ABSTRACT FROM AUTHOR]

In this work, the commercial detonation nanodiamonds (DNDs) are introduced to the anodes of lithium ion battery (LIBs) consisting of anatase titanium dioxide (TiO2) and synthesized graphite by a microwave treatment process. The compound TiO2/DND/graphite anodes are favorable for improving the LIB performance, where the LIBs have lithium storage capacities of 540 mA h g−1 at 0.5 C after 100 cycles and 300 mA h g−1 at 5 C after 1000 cycles, which are greatly higher than the theoretical data (168 mA h g−1) from TiO2 anode alone. The high capacity, as well as excellent cycling performance and stability of the LIBs, are attributed to the synergistic effect of DND (larger surface area, low expansion, high lithium adsorption capacity, chemical inertness), TiO2 (high Li+ insertion/extraction voltage, robust structural stability, lower volumetric expansion) and the improved ionic conductivity of the anode with additional fabricated graphitic powders. [ABSTRACT FROM AUTHOR]

Doping carbon materials with p‐block elements such as nitrogen is an effective approach to tune electronic properties of the framework and can endow the host's new characters. To date, highly doped carbons with tunable nitrogen speciation are still less explored due to the grand challenge in fabrication; for example, the typical synthesis based on the pyrolysis of nitrogen‐containing precursors shows a trade‐off between the total nitrogen content and the carbonization temperature, limiting the value to ≈12 wt% at 1073 K. Herein, intensifying ring opening of cross‐linked polymers through controlled pre‐oxidation followed by conventional pyrolysis is demonstrated as an elegant method to circumvent this challenge. In addition to fine tunability at different nitrogen speciation, this strategy can increase the nitrogen content by two‐ to threefold (maximum ≈22 wt%) and shows general viability in six different N‐bearing (co)polymers. The highly doped pyridinic nitrogen‐rich carbons show i) a remarkable capacity of 879 mAh g−1 at 0.1 A g−1 and excellent cycling performance in lithium ion batteries, and ii) significantly boosted catalytic performance in the selective oxidation of diverse substrates. Therefore, this facile synthetic strategy and the tunability at nitrogen functionalities will greatly broaden the applications of this new class of functional materials. [ABSTRACT FROM AUTHOR]

Reasonably designing and synthesizing advanced electrode materials is significant to enhance the electrochemical performance of lithium ion batteries (LIBs). Herein, a metal–organic framework (MOF, Mil‐125) was used as a precursor and template to successfully synthesize the porous mooncake‐shaped Li4Ti5O12 (LTO) anode material assembled from nanoparticles. Even more critical, SmF3 was used to modify the prepared porous mooncake‐shaped LTO material. The SmF3‐modified LTO maintained a porous mooncake‐shaped structure with a large specific surface area, and the SmF3 nanoparticles were observed to be attach on the surface of the LTO material. It has been proven that the SmF3 modification can further facilitate the transition from Ti4+ to Ti3+, reduce the polarization of electrode, decrease charge transfer impedance (Rct) and solid electrolyte interface impedance (Rsei), and increase the lithium ion diffusion coefficient (DLi), thereby enhancing the electrochemical performance of LTO. Therefore, the porous mooncake‐shaped LTO modified using 2 wt % SmF3 displays a large specific discharge capacity of 143.8 mAh g−1 with an increment of 79.16 % compared to pure LTO at a high rate of 10 C (1 C=170 mAh g−1), and shows a high retention rate of 96.4 % after 500 cycles at 5 C‐rate. [ABSTRACT FROM AUTHOR]

Due to advantages such as low environmental impact, low price, and high theoretical specific capacity, Co3O4 has been widely studied. However, its low conductivity and volume expansion during the charging and discharging processes caused pulverization and agglomeration ultimately leads to a rapid decline in battery capacity during the cycle. The creation of nano structured composite of carbon materials and Co3O4 can be used to form a highly conductive matrix that improves the electronic conductivity, and improves the dispersion of Co3O4 to reduce agglomeration and volume expansion. In this work, the rigid conjugated plane structure of 1,10‐phenanthroline was selected to coordinated with cobalt nitrate to form a precursor complex. After heating, the crystal core of Co3O4 becomes more uniform in size with a more regular geometry. Additionally, a calcining temperature of 350 °C was shown to result in an optimal amount of carbon residue that improved electronic conductivity of the whole composite while not excessively hindering lithium‐ion transport. As a result, these properties improved the electron conductivity and protect the crystals from damage caused by volume change during charge and discharge to a certain extent, thus contributing to improved electrochemical performance. [ABSTRACT FROM AUTHOR]

Due to the large reversible capacity, high operating voltage and low cost, layered ternary oxide cathode materials LiNixCoyAl1−x−yO2(NCA) and LiNixCoyMn1−x−yO2(NCM) are considered as the most potential candidate materials for lithium‐ion batteries (LIBs) used in (hybrid) electric vehicles (EVs). However, next‐generation long‐range EVs require a high specific capacity (around 203 mAh·g–1at 3.7V) at the cathode active material level, which is not provided with current commercially layered ternary oxide cathodes. Increasing the operating voltage is an effective method to improve the specific capacity of the cathode and the energy density of the battery, but the high operating voltage also causes a lot of problems, such as cation mixing and phase transformation, electrolyte decomposition, transition metal dissolution and microcracks. So far, researchers have carried out a lot of works to solve these issues. Surface coating, element doping and the design of electrolytes have been proved to be effective solutions. In this review, the failure mechanisms and modification methods of high‐voltage layered ternary oxide cathode materials are summarized, which could provide valuable information to the research of high‐voltage layered ternary oxide cathode materials in basic science and industrial production. [ABSTRACT FROM AUTHOR]

Accurate and fast prediction of the remaining useful life of lithium (Li) ion batteries is an important requirement for successful electrification of automobiles. Consequently, there is a growing interest in the development of reduced‐order models. The existing reduced‐order electrochemical models can be used to predict battery performance (state of charge [SoC], terminal voltage) when the current through the battery is known a priori. Therefore these models cannot be used for studying the constant voltage (CV) mode of the constant current‐CV (CC‐CV) charging protocol, which is a common battery charging mechanism. In this work, we propose a reduced‐order electrochemical model to estimate the battery SoC under CC‐CV charging conditions, along with an analytical expression to approximate the CV mode charging time. We further propose a framework that accounts for the influence of the battery state of health (SoH) on the battery SoC during an operating cycle and vice‐versa. The proposed framework for estimating the battery SoC and SoH in a coupled manner shows good comparison with a first principles electrochemical model for CC‐CV charging conditions. This model can be used to study battery ageing and it can find applications in real‐time state estimation, charge protocol optimization, and battery design. [ABSTRACT FROM AUTHOR]

Silicon has attracted a lot of attention as a potential anode material for next‐generation lithium ion batteries (LIBs) because of its high energy density, high theoretical capacity, and abundance. Herein, we introduce an effortless synthesis of coral‐like silicon powders with a three‐dimensional (3D) interlinked network using a scalable method that consist of magnesiothermic reduction and chemical vapor deposition. The porous structure achieved by silicon nanospheres can create room for the volume expansion and alleviate the built strain that would occur upon lithiation. In addition, intertwined coral‐like framework provides a shortened path for lithium ion diffusion, which can improve the ionic conductivity of the cells. At a high current rate of C/2, a reversible capacity of 3172 mAh g−1 was delivered by the silicon‐carbon nanocomposite electrode, and the capacity still remains as high as 1018 mAh g−1 after 500 cycles, while the Columbic efficiency is higher than 99%. The inexpensive, effective, and scalable fabrication of porous silicon‐carbon nanocomposite spheres possessing a 3D interlinked network could establish a basis for developing high energy density anode materials to be used in next‐generation LIBs. [ABSTRACT FROM AUTHOR]

The main researches focus on the recovery of metal elements in lithium manganate and not consider regenerating the cathode scrap materials. In this study, first, the polyvinylidene fluoride (PVDF) binder is removed by a combination of solvent dissolution and heat treatment. PVDF is easily separated by dissolving in an N‐methyl‐2‐pyrrolidone solution at a heating temperature of 60 °C, stirring time of 50 min, and solid solution ratio of 80 g⋅L−1. The dissolution rate of the scrap material achieves 86.70 % under optimal conditions. Further, using inductively coupled plasma spectroscopy to define the Li and Mn metal contents, and the LiMn2O4 cathode material is regenerated by a hydrometallurgical method. At the optimum calcination conditions of 500 °C for 12 h, electrochemical performance show that there are obvious charge and discharge platforms in the charge/discharge curves, and high first‐cycle discharge capacity is 123.7 mAh g−1 (3.0–4.3 V and 0.1 C), after 50 cycles, it decrease to 83.2 mAh g−1. [ABSTRACT FROM AUTHOR]

Two‐dimensional metal sulfides and their hybrids are emerging as promising candidates in various areas. Yet, it remains challenging to synthesize high‐quality 2D metal sulfides and their hybrids, especially iso‐component hybrids, in a simple and controllable way. In this work, a low‐temperature selective solid‐liquid sulfidation growth method has been developed for the synthesis of CuS nanoflakes and their hybrids. CuS nanoflakes of about 20 nm thickness and co‐component hybrids CuOx/CuS with variable composition ratios derived from different sulfidation time are obtained after the residual sulfur removal. Besides, benefiting from the mild low‐temperature sulfidation conditions, selective sulfidation is realized between Cu and Fe to yield iso‐component FeOx/CuS 2D nanoflakes of about 10–20 nm thickness, whose composition ratio is readily tunable by controlling the precursor. The as‐synthesized FeOx/CuS nanoflakes demonstrate superior lithium storage performance (i. e., 707 mAh g−1 at 500 mA g−1 and 627 mAh g−1 at 1000 mA g−1 after 450 cycles) when tested as anode materials in LIBs owing to the advantages of the ultrathin 2D nanostructure as well as the lithiation volumetric strain self‐reconstruction effect of the co‐existing two phases during charging/discharging processes. [ABSTRACT FROM AUTHOR]

Heterostructure engineering of electrode materials, which is expected to accelerate the ion/electron transport rates driven by a built‐in internal electric field at the heterointerface, offers unprecedented promise in improving their cycling stability and rate performance. Herein, carbon nanotubes with Co9S8/ZnS heterostructures embedded in a N‐doped carbon framework (Co9S8/ZnS@NC) have been rationally designed via an in‐situ vapor chemical transformation strategy with the aid of thiophene, which not only acted as carbon source for the growth of carbon nanotubes but also as sulfur source for the sulfurization of metal Zn and Co. Density functional theory (DFT) calculation shows an about 3.24 eV electrostatic potential difference between ZnS and Co9S8, which results in a strong electrostatic field across the interface that makes electrons transfer from Co9S8 to the ZnS side. As expected, a stable cycling performance with reversible capacity of 411.2 mAh g−1 at 1000 mA g−1 after 300 cycles, excellent rate capability (324 mAh g−1 at 2000 A g−1) and a high percentage of pseudocapacitance contribution (87.5% at 2.2 mv/s) for lithium‐ion batteries (LIBs) are achieved. This work provides a possible strategy for designing multicomponent heterostructural materials for application in energy storage and conversion fields. [ABSTRACT FROM AUTHOR]

The decomposition of state‐of‐the‐art lithium ion battery (LIB) electrolytes leads to a highly complex mixture during battery cell operation. Furthermore, thermal strain by e.g., fast charging can initiate the degradation and generate various compounds. The correlation of electrolyte decomposition products and LIB performance fading over life‐time is mainly unknown. The thermal and electrochemical degradation in electrolytes comprising 1 m LiPF6 dissolved in 13C3‐labeled ethylene carbonate (EC) and unlabeled diethyl carbonate is investigated and the corresponding reaction pathways are postulated. Furthermore, a fragmentation mechanism assumption for oligomeric compounds is depicted. Soluble decomposition products classes are examined and evaluated with liquid chromatography‐high resolution mass spectrometry. This study proposes a formation scheme for oligo phosphates as well as contradictory findings regarding phosphate‐carbonates, disproving monoglycolate methyl/ethyl carbonate as the central reactive species. [ABSTRACT FROM AUTHOR]

Owing to the high specific capacity and energy density, metal oxides have become very promising electrodes for lithium‐ion batteries (LIBs). However, poor electrical conductivity accompanied with inferior cycling stability resulting from large volume changes are the main obstacles to achieve a high reversible capacity and stable cyclability. Herein, a facile and general approach to fabricate SnO2, Fe2O3 and Fe2O3/SnO2 fibers is proposed. The appealing structural features are favorable for offering a shortened lithium‐ion diffusion length, easy access for the electrolyte and reduced volume variation when used as anodes in LIBs. As a consequence, both single and hybrid oxides show satisfactory reversible capacities (1206 mAh g−1 for Fe2O3 and 1481 mAh g−1 for Fe2O3/SnO2 after 200 cycles at 200 mA g−1) and long lifespans. [ABSTRACT FROM AUTHOR]

Organic redox active molecules are the promising electrode materials for the Lithium‐ion batteries (LIBs). The semiconducting nature and morphology of these materials provide more efficient charge transport. Hence, it is very important to perform systematic study of such molecules. Herein, we proposed single step synthesis of the benzoic naphthalene diimide (Benzoic‐NTCDI) by the reaction of 1, 4, 5, 8‐ naphthalene tetracarboxylic dianhydride with 4‐amino benzoic acid in presence of hydrated zinc acetate as a catalyst. As‐synthesized benzoic NTCDI is characterised by using different characterization techniques. The morphological study clearly demonstrate hierarchical porous assembly of 3–5 micron comprised with nanopetals of thickness 5–10 nm. In this hierarchical nanostructure, the nanopetals are originated from the centre and confer voids between the layers of petals. This creates porosity throughout the hierarchical assembly. Considering such unique porous nanostructure and good conductivity of the Benzoic‐NTCDI (1.19×10−5 S/m), it has been used as a cathode for LIB.The Li‐cell was fabricated using Benzoic‐NTCDI as a cathode which demonstrated the reversible capacity of 102 mAhg−1 at 0.05 C rate. Moreover, the capacity of 91 mAhg−1 is retained at current density of 0.1 C exhibiting good rate capability after 24 cycles. The Li‐ion transport has been accelerated is ascribed to the porous hierarchical nanostructure. The potential of one of the heterocyclic molecule with hierarchical nanostructure as a cathode for lithium ion batteries (LIBs) has been demonstrated for the first time [ABSTRACT FROM AUTHOR]

Advanced anode materials with high rate performance and high safety are greatly desired for power lithium ion batteries. Herein, one‐dimensional WNb2O8 is synthesized via a simple solution method with succeeding thermal calcining, and is first employed as an anode material for power lithium ion batteries. WNb2O8 nanorods with diameters of 100–200 nm reveal a reversible capacity of 229.2 mAh g−1 with high initial coulombic efficiency of 92 % at 0.2 C. WNb2O8 nanorods also possess high rate performance (150.7 mAh g−1 at 10 C) and cycling stability (keeping 85.2 % of the initial capacity after 500 cycles at 5 C). Moreover, the calculation results prove that the intercalation pseudocapacitance, which is promoted by ultrahigh lithium ion diffusion efficiency, plays a significant role in the fast charge/discharge processes. [ABSTRACT FROM AUTHOR]

Organic lithium ion batteries (LIBs) are considered as one of the next‐generation green electrochemical energy storage (EES) devices. However, obtaining both high capacity and long‐term cyclability is still the bottleneck of organic electrode materials for LIBs because of weak structural and chemical stability and low conductivity. Covalent organic frameworks (COFs) show potential to overcome these problems owing to its good stability and high capacity. Herein, the synthesis and characterization of two π‐conjugated COFs, derived from the Schiff‐base reaction of 2,4,6‐triaminopyrimidne (TM) respectively with 1,4‐phthalaldehyde (PA) and 1,3,5‐triformylbenzene (TB) by a mechanochemical process are presented. As anode materials for LIBs, the COFs exhibit favorable electrochemical performance with the highest reversible discharge capacities of up to 401.3 and 379.1 mAh g−1 at a high current density (1 A g−1), respectively, and excellent long‐term cyclability with 74.8 and 72.7 % capacity retention after 2000 cycles compared to the initial discharge capacities. [ABSTRACT FROM AUTHOR]

Manganese monoxide (MnO) is a promising anode material for lithium ion batteries, but it often shows poor electrochemical performance due to some inevitable drawbacks including intrinsic low electrical conductivity, poor stability, and severe polarization. In this work, a 1D core‐shell MnO@S, N co‐doped carbon material (MnO@SNC) was obtained by pyrolysis of MnO2@PPy precursor at 600 °C in N2 atmosphere. When evaluated as an anode for lithium ion batteries, the unique structure and composition advantages endow the as‐formed material with excellent lithium storage performance in terms of high specific capacity (955.5 mAh g−1 at a current density of 500 mA g−1), long‐term cycling stability (up to 500 cycles), and superior rate capability (458.7 mAh g−1 at a current density of 2 A g−1). The outstanding electrochemical performance could be attributed to the unique 1D core‐shell structure, abundant graphited carbon and MnO nanorods. [ABSTRACT FROM AUTHOR]

A unique nitrogen and oxygen dual‐doped three‐dimensional porous carbon derived from nori which can be produced in large‐scale is used as conductive matrix to solve the problem of low conductivity of FeF3⋅0.33H2O cathode. Carbon with abundant channels combine with FeF3⋅0.33H2O nanoparticles to form a micro‐nanostructure material. The combination of small nanoparticles and highly conductive three dimension porous carbon skeleton forms a high‐speed ion and electron transport network which benefit the Li‐storage performance of FeF3⋅0.33H2O. The as‐prepared composite possess a capacity of 170, 157, and 104 mAh g−1 at 1 C, 2 C, and 20 C in lithium‐ion batteries which is much better than bulk FeF3⋅0.33H2O. Moreover, the capacity still maintains at 101 mAh g−1 after 500 times charge/discharge at a current density of 5 C. [ABSTRACT FROM AUTHOR]

Nanostructured tin dioxide (SnO2) has emerged as a promising anode material for lithium‐ion batteries (LIBs) due to its high theoretical capacity (1494 mA h g−1) and excellent stability. Unfortunately, the rapid capacity fading and poor electrical conductivity of bulk SnO2 material restrict its practical application. Here, SnO2 nanospheres/reduced graphene oxide nanosheets (SRG) are fabricated through in‐situ growth of carbon‐coated SnO2 using template‐based approach. The nanosheet structure with the external layer of about several nanometers thickness can not only accommodate the volume change of Sn lattice during cycling but also enhance the electrical conductivity effectively. Benefited from such design, the SRG composites could deliver an initial discharge capacity of 1212.3 mA h g−1 at 0.1 A g−1, outstanding cycling performance of 1335.6 mA h g−1 after 500 cycles at 1 A g−1, and superior rate capability of 502.1 mA h g−1 at 5 A g−1 after 10 cycles. Finally, it is believed that this method could provide a versatile and effective process to prepare other metal‐oxide/reduced graphene oxide (rGO) 2D nanocomposites. [ABSTRACT FROM AUTHOR]

We investigated the applicability of an ionic liquid electrolyte to a phosphorus‐doped Si (P‐doped Si) electrode to improve the performance and safety of the lithium‐ion battery. The electrode exhibited excellent cycling performance with a discharge capacity of 1000 mA h g−1 over 1400 cycles in the ionic liquid electrolyte, whereas the capacity decayed at the 170th cycle in the organic electrolyte. The lithiation/delithiation reaction of P‐doped Si occurred a localized region in the organic electrolyte, which generated a high stress and large strain. The strain accumulated under repeated charge‐discharge cycling, leading to severe electrode disintegration. In contrast, the reaction of P‐doped Si proceeded uniformly in the ionic liquid electrolyte, which suppressed the electrode disintegration. The P‐doped Si electrode also showed good rate performance in the ionic liquid electrolyte; a discharge capacity of 1000 mA h g−1 was retained at 10 C. A P‐doped Si electrode exhibited excellent cycling performance with a discharge capacity of 1000 mA h g−1 over 1400 cycles in an ionic liquid electrolyte, whereas the capacity decayed at approximately the 170th cycle in an organic electrolyte. It is concluded that the ionic liquid electrolytes could be successfully applied to a P‐doped Si electrode and that they represent one type of promising electrolyte for next‐generation LIBs with this electrode. [ABSTRACT FROM AUTHOR]

Though molybdenum dioxide (MoO2) has attractive properties, conductivity is still threat to its implementation as it is very low compared to graphite. Herein, we have come up with MoO2‐rGO nanocomposite to mitigate this drawback, where nano sized MoO2 particles have been synthesised and supported with graphene sheets. Several physicochemical characterization techniques have been used to confirm the desired state of the obtained material. In this report, rGO supported MoO2 nanoparticles have been investigated as an anode for lithium ion battery and its electrochemical properties have been extensively studied. The new architecture exhibits excellent electrochemical performance by delivering a high discharge capacity of 1205 mA h g−1 even after 100 cycles. It also exhibits good rate capability by delivering discharge capacities of 809, 753, 675 mA h g−1 at current rates of 1 C, 3 C and 5 C, respectively. Simple inert annealing method was adopted to synthesize MoO2 NPs. The obtained MoO2 are composited with rGO by hydrothermal treatment. In the present work, MoO2‐rGO nanocomposite was probed as anode for lithium ion batteries. The electrochemistry of MoO2 is scrutinized by comparative study between MoO2 NPs, MoO2‐rGO nanocomposite and commercial MoO2. MoO2‐rGO delivered a enhanced discharge capacity of 1205 mA h g−1 and excellent stability over 100 cycles at current rate of 0.1 C. [ABSTRACT FROM AUTHOR]

We report a spatially‐confined strategy to improve the cycling stability of tin‐based anode materials, in which carbon acted as passenger particle is implanted in suit into the secondary structure of porous tin dioxide (SnO2), forming a spatial fault structure together with the SnO2 particles. Herein, the carbon (C) surrounding is endowed with the dual roles, which can not only prevent SnO2 and tin (Sn) nanoparticles aggregating for a better cycling stability, but also can improve the electron transport at the particle interface for high rate performance of the battery. Also, rigid titanium dioxide (TiO2) cavities are constructed for positive mechanical protections and releasing the mechanical stress to further improve the stability of the battery. Electrochemical tests reveal that such spatially‐confined architectures can enhance the cycling stability and improve the rate properties of tin‐based anode batteries remarkably. The discharge specific capacity of the spatial confined samples can be maintained 520 mAh g‐1 after 100 cycles at 0.2C and 320 mAh g‐1 at a high current rate of 1C. A spatially‐confined strategy is proposed to improve the cycling stability of tin‐based anode materials, in which carbon acted as the passenger particle is implanted in suit into the secondary structure of porous SnO2, forming a spatial fault structure together with the SnO2 particles. Also, rigid TiO2 cavities are constructed for accommodating SnO2‐C spheres to resist a huge pressure generated from lithium insertion. [ABSTRACT FROM AUTHOR]

Many strategies have been adapted to improve the stability of silicon (Si) based anodes, one of the widely studied methods is to make Si‐graphene (Si−Gr) materials, all have adapted the sandwiched structure of Si−Gr or Si‐graphene oxide (Si‐GO) where Si nanoparticles (NP) are sandwiched between Gr based materials. Herein, we report a simple strategy to achieve Si−Gr based anode with a different structure than that of the intercalated structure, which is expected to provide better stability to the Si−Gr based anode, i. e. a core‐shell structure. This core‐shell structure based on a Si‐nanographene oxide (Si‐nGO) delivers an initial reversible specific capacity of ∼2000 mAhg−1 and stability of ≥ 250 cycles with 80% capacity retention at an active material (AM) AM mass loading of 1.5 mg cm−2, and at ∼2.0 mg cm−2, ∼160 cycles stability was achieved, which is one of the best reported values, meanwhile, intercalated Si‐graphene oxide (Si‐GO) exhibited only < 50 cycles stability at ∼2.0 mg cm−2 mass loading. Higher current rate performance of Si‐nGO was ∼70% retention of the initial capacity at 5 C, whereas Si‐GO retention was < 25% at 5 C. Thus a change in the structure of Si−Gr based anode has improved the stability remarkably and shows that it is a promising strategy towards achieving electrode material for advanced lithium‐ion batteries (LIBs). Text for Table of Contents: A core‐shell Si−Gr based anode, Si‐nGO is reported which exhibits superior capacity, cycle life and rate performance, and is expected to convey a great impact in the field of sustainable materials for advanced energy storage applications. [ABSTRACT FROM AUTHOR]

Abstract: Solid polymer electrolytes (SPEs) promise to improve the safety and performance of lithium ion batteries (LIBs). However, the low ionic conductivity and transference number of conventional poly(ethylene oxide) (PEO)‐based SPEs preclude their widespread implementation. Herein, crosslinked poly(tetrahydrofuran) (xPTHF) is introduced as a promising polymer matrix for “beyond PEO” SPEs. The crosslinking procedure creates thermally stable, mechanically robust membranes for use in LIBs. Molecular dynamics and density functional theory (DFT) simulations accompanied by 7Li NMR measurements show that the lower spatial concentration of oxygen atoms in the xPTHF backbone leads to loosened O–Li+ coordination. This weakened interaction enhances ion transport; xPTHF has a high lithium transference number of 0.53 and higher lithium conductivity than a xPEO SPE of the same length at room temperature. It is demonstrated that organic additives further weaken the O–Li+ interaction, enabling room temperature ionic conductivity of 1.2 × 10−4 S cm−1 with 18 wt% N,N‐dimethylformamide in xPTHF. In a solid‐state LIB application, neat xPTHF SPEs cycle with near theoretical capacity for 100 cycles at 70 °C, with rate capability up to 1 C. The plasticized xPTHF SPEs operate at room temperature while maintaining respectable rate capability and capacity. The novel PTHF system demonstrated here represents an exciting platform for future studies involving SPEs. [ABSTRACT FROM AUTHOR]

High energy demand has directed the present‐day research towards synthesis and applications of heterostructured nanomaterials such as molybdenum oxysalts over mono‐structured nanomaterials. Molybdenum oxysalt is a promising anode material for lithium ion batteries because of its high theoretical lithium storage capacity (998 mAh g−1) and flexible composition. Engineering the morphology and porosity of a material has proven to be a productive approach towards enhancing its performances. Here in, we have demonstrated a one pot synthesis of mesoporous MnMoO4 nanorods and its enhanced electrochemical performance for Li‐ion battery anode. Several physiochemical techniques have been used to validate the desired properties and purity of the synthesized material. It exhibits high lithiation capacity of 1050 mAh g−1 and stability over 100 cycles at 0.5 C. The enhanced performance is attributed to its structural stability and mesoporous nature. [ABSTRACT FROM AUTHOR]

Abstract: In searching for polymer‐based electrolytes with improved performance for lithium ion and lithium metal batteries, we studied block copolymer electrolytes with high amounts of bis(trifluoromethane)sulfonimide lithium obtained by macromolecular co‐assembly of a poly(isoprene)‐block‐poly(styrene)‐block‐poly(ethylene oxide) and the salt from tetrahydrofuran. Particularly, an ultra‐short poly(ethylene oxide) block of 2100 g mol−1 was applied, giving rise to 2D continuous lamellar microstructures. The macroscopic stability was ensured with major blocks from poly(isoprene) and poly(styrene), which separated the ionic conductive PEO/salt lamellae. Thermal annealing led to high ionic conductivities of 1.4 mS cm−1 at 20 °C with low activation energy and a superior lithium ion transference number of 0.7, accompanied by an improved mechanical stability (storage modulus of up to 107 Pa). With high Li:O ratios >1, we show a viable concept to achieve fast Li+ transport in block copolymers (BCP), decoupled from slow polymer relaxation. [ABSTRACT FROM AUTHOR]

Co3O4 is regarded as a competent anode material for lithium and sodium ion batteries having high theoretical capacity of 890 mAh g‐1 obtained through metal displacement reaction with Li or Na. Nano Co3O4 consisting of 20–30 nm‐sized particles was synthesized through a simple precipitation method and characterized through X‐ray diffraction, Fourier‐transform infrared spectroscopy, scanning electron microscopy, Transmission electron microscopy and X‐ray photoelectron spectroscopy. Electrochemical evaluation of the nano Co3O4 as anode material for Li‐ion and Na‐ion batteries was performed through cyclic voltammetry, electrochemical impedance spectroscopy and charge‐discharge cycling studies. Nano Co3O4 delivered high discharge capacity of 423 mAh g‐1 at 0.1 C even after 40 cycles as Li‐ion battery anode and exhibited stable discharge behaviour up to 130 cycles with high rate capability. Nano Co3O4 in Na‐ion configuration delivered discharge capacity of 101 mAh g‐1 at 0.1 C rate even after 30 cycles. At higher current rates Co3O4 electrodes exhibited severe capacity fading due to the huge volume change occurred during sodiation / desodiation. Ex‐situ SEM and elemental analyses evidenced that disintegration of electrode structure resulting from volume change and continuous decomposition of electrolyte were responsible for the poor electrochemical performance of Co3O4 with Na+ ions while in Li‐ion configuration nano Co3O4 outshined in cycling performance. [ABSTRACT FROM AUTHOR]

Abstract: The ions transport channel like network structure is build between active materials, due to its unique low dimensional properties. Microstructure indicates that the tiny LiFePO4 nanoparticles with average size of ≈7–9 nm embedded in the amorphous carbon matrix. When the LiFePO4‐CNFs is directly applied as flexible cathode electrode for lithium‐ion battery, which has high initial discharge capacity of 134 mAh g−1 at 0.5 C (1C = 170 mAh g−1) rate and stability cycling performance after 300 cycles. Further electrochemistry investigation reveals that the flexible one‐dimentional structure of CNFs enable it to release the mechanical deformation resulting from lithium ion insert and extract the electrodes, which resulted in a superior diffusion coefficient of lithium ions up to 2.4 × 10−12 cm2 s−1. [ABSTRACT FROM AUTHOR]

Abstract: Spinel structured nanomaterials have shown good stability for lithium ion storage applications. Among all, Li4Ti5O12 (LTO) anode and LiMn2O4 (LMO) cathode is a potential combination for high energy and high power applications. In the present work, we utilize this specific combination to fabricate full‐cells in combination with carbon nanostructures as additives. Typically, 20–25 nm sized LTO and 200–500 nm sized LMO nanoparticle electrodes are composited with carbon nanostructures including, carbon nanotube (CNT), carbon black (CB) and graphene nanoplatelets (GNP). High rate performance of respective half‐cells (lithium metal as counter electrode) of LTO and LMO are tested up to 50C. It was found that half‐cells with CNT additive retained almost 80% of its 1C rate capacity at 50C rate. Also both the electrodes exhibited 1000 cycles stability with retention of about 80% at 10C rate cycling. Using these CNT additive based electrodes, a full‐cell fabricated and tested exhibited high capacity and stable cycling over 500 cycles at 1000 mA/g specific current. The full‐cell delivered power density of about 2310 W/kg and energy density of about 140 Wh/kg that can be further improved for high power Li‐ion battery technology. [ABSTRACT FROM AUTHOR]

Abstract: Mn‐based active materials, such as LiMn2O4, are widely used for positive electrodes in lithium ion batteries, and spinel LiNi0.5Mn1.5O4 is drawing much attention to realize 5‐V class batteries. However, the oxidative decomposition of electrolyte solution at high voltages and Mn‐dissolution of LiNi0.5Mn1.5O4 are serious problems to be solved. These two drawbacks are more marked at elevated temperatures, and should be caused by free solvent molecules in electrolyte solution. In this study, highly concentrated electrolyte solution, which contains few free solvent molecules, was investigated to solve the problems. LiNi0.5Mn1.5O4 electrodes worked at 50oC in nearly saturated 7.25 mol kg−1 LiBF4/ propylene carbonate (PC) electrolyte solution, whereas not in the nearly saturated 4.30 mol kg−1 LiPF6/PC. In addition, Mn‐ion dissolution from LiNi0.5Mn1.5O4 was significantly suppressed in highly concentrated electrolyte solutions, and correlated to the fraction of free PC molecules in them. [ABSTRACT FROM AUTHOR]

In this study, the authors report the highly efficient, multigram-scale synthesis of an ester-functionalized, poly(aniline-co-fluorene) polymer. The excellent solubility and film-forming ability of this polymer facilitate its application as a reversible battery cathode. Electrochemical quartz crystal microbalance with dissipation monitoring confirms a multi-electron transfer process, resulting in a specific discharge capacity of 51 mAh g−1 and a high reversible doping level of 0.69. Galvanostatic cycling at 1 C demonstrates excellent electrode stability with a capacity retention of 95.2% after 100 cycles. Therefore, this work demonstrates a novel electroactive polymer that exemplifies how chemical functionality may be used to properly balance processability and electroactivity of macromolecular battery cathodes. [ABSTRACT FROM AUTHOR]