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Sulfide-based glasses and glass-ceramics showing high ionic conductivities and excellent mechanical properties are considered as promising solid-state electrolytes. Nowadays, the computational material techniques with the advantage of low research cost are being widely utilized for understanding, effectively screening and discovering of battery materials. In consideration of the rising importance and contributions of computational studying on the glassy SSE materials, here, this work summarizes the common computational methods utilized for studying the amorphous inorganic materials, review the recent progress in computational investigations of the lithium and sodium sulfide-type glasses for solid-state batteries, and outlines our understandings of the challenges and future perspective on them. This review would facilitate and accelerate the future computational screening and discovering more glassy-state SSE materials for the solid-state batteries.

This work studies the kinetic behaviors of Li–S chemistry on Mo-based compounds (MCNs-MoXn, X = O, S, N, P), and it is found that the Li–S battery using the MoP-modified separator exhibits superior rate and long cycle performance.

A carbonate-based electrolyte is well-designed via a multifunctional lithium difluorobis(oxalato) phosphate (LiDFBOP) additive, endowing 4.5 V sodium metal batteries with high energy density, excellent cycling stability and a wide temperature range.

High-energy-density CFx/Li batteries have attracted wide applications, but encountered poor environmental adaptability at high/low temperatures. Guided with unique electrolyte-involved reaction mechanism, propylene carbonate (PC)/methyl butyrate (MB) co-solvent formulation was optimized to tune the desolvation barrier and stability for wide temperature operation. Weak affinity of Li+-MB and unique solvation structure of electrolyte, which facilitated easy desolvation at both high rate and low temperature, were uncovered with theoretical calculations and spectra characterizations. Desolvation process from intermediate and percolation-type reaction were clearly revealed with in-situ FT-IR and ex-situ TEM. The synergistic effect of handy desolvation with fast kinetics at the interface enabled excellent rate performance (1C, 834 mAh g−1) at +25°C and high capacity (240 mAh g−1) at low temperature of -70°C. Simultaneously, the stability of electrolyte assisted to realize high-temperature tolerance up to +95°C. The mechanism-guided electrolyte design offers deep understanding and novel strategy to improve CFx/Li batteries for wide temperature applications.

Rechargeable aqueous zinc-ion batteries (AZBs) are potentially considered as potential alternatives for large-scale stationary energy storage systems by taking advantage of their easy operating con...

Amphoteric water electrolysis with a bipolar membrane can accommodate optimal pH conditions simultaneously for both cathode and anode under steady-state operation without changing the overall thermodynamics of water splitting. However, the high voltage loss of bipolar membrane imposes significant constraints on operating current density, leading to low current density (

Iron-based phosphate materials have been employed as cathodes for sodium-ion batteries (SIBs) because of their low cost and environmental friendliness, but the electrochemical performance of this k...

Prussian blue analogues (PBAs) have been widely investigated as cathode materials in aqueous Na-ion batteries (ASIBs) due to their special open-framework structure. Herein, nanoscale nickel hexacya...

Investigating the reaction mechanism and the rational design of highly efficient electrocatalysts for the oxygen evolution reaction play a key role in renewable energy applications. Here, we report a homogeneous multi-metal-site oxyhydroxide electrocatalyst (consisting of Fe doped NiOOH and Cu doped NiOOH) obtained by in situ electrochemical dealloying of the multi-metal-site alloy (consisting of FeNi3 and NiCu alloys). The in situ structural evolution process manipulates the intermediate and enhances the water oxidation performance. After dealloying, the electrochemically dealloyed catalyst exhibits a small overpotential at large current density (250 mV at 100 mA cm−2), low Tafel slope (34 mV dec−1), remarkably increased ECSA (8-fold larger than before), and superior durability for 200 h at 100 mA cm−2. This electrocatalyst presents one of the best performances among all reported transition metal-based electrocatalysts, and is even superior to the benchmark RuO2. Operando ATR FT-IR reveals that the electrochemically dealloyed electrocatalyst could manipulate the reaction path based on direct O2 evolution mechanism (DOEM) and facilitate the formation of O–O bonds. This fundamental understanding will contribute to the identification and design of the active structure of oxygen evolution electrocatalysts.

With the increase in interest in energy storage for grid applications, a rechargeable battery, as an efficient energy storage/conversion system, has been receiving great attention. However, its development has largely been stalled by the issues of high cost, safety and energy density. Here, we report an aqueous manganese–lead battery for large-scale energy storage, which involves the MnO2/Mn2+ redox as the cathode reaction and PbSO4/Pb redox as the anode reaction. The redox mechanism of MnO2/Mn2+ was investigated to improve reversibility. All materials are inexpensive and the assembled battery can work well during the penetration test. The battery shows a discharge voltage of around 1.55 V, high rate capability, and no obvious capacity decay over 10 000 cycles. Furthermore, a high volumetric low energy density of 187 W h L−1 was obtained for a pouch battery using a high-concentration electrolyte comprising 3 M MnSO4. Meanwhile, the low freezing point of the high-concentration electrolyte endowed the battery with capability to work at a low temperature of −40 °C. Owing to the low cost and high electrochemical performance, the Mn–Pb battery has great potential for grid energy storage.

Abundant flake-porous Na3Fe2(PO4)3 has been prepared via a simple spray drying method. As a cathode material in sodium-ion batteries (SIBs), the galvanostatic charge/discharge test results indicate...

Various artificial interlayers like metal/metallic oxides have been introduced to improve Li wettability through alloy reaction for the Li/garnet interface. However, huge volume change during the c...

Lithium-sulfur battery is garnering much of attention due to its high energy densities, low-cost active material of sulfur and variety of applications in portable electronics. High integrity and consistent qualities of the large-scale sulfur cathode with high energy have to be ensured to construct reliable and practical lithium-sulfur batteries that could supersede advancing lithium-ion batteries. Here, facile and productive approaches are developed to mass-produce functional sulfur hosts and to fabricate large-scale sulfur cathode with high sulfur loading. The functional sulfur host is synthesized by anchoring polyethylenimine at the surface of commercially available carbon at inert conditions with a scale of more than 10 g per batch via simple solution method. Combining the functionalized sulfur host with a polyacrylic acid binder allows high integrity and uniformity of the high sulfur loading cathode to be fabricated in large dimensions. Followed by this approach, the sulfur cathode, 70 × 6 cm2, is produced with the sulfur loading of >4.3 mg cm−2. It is found that 12 wt% of polyethylenimine in the functionalized sulfur host with polyacrylic acid is at optimal condition that presents stable electrochemical performances over 600 cycles.

Titanosilicate sitinakite compound with an ideal formula of Na1.68H0.32Ti2O3SiO4·1.76H2O (NTSO) has been employed as a low intercalation potential anode for rechargable sodium ion batteries (SIBs),...

Batteries with Li metal anodes have the desirable feature of high energy density; however, the notorious problem of Li dendrite formation has impeded their practical applications. Herein, we present a versatile single-ion electrolyte, which is achieved by a different strategy of coordinating the anions in the electrolyte on the open metal sites of a metal organic framework. Further investigations of the activation energy and theoretical quantum mechanical calculations suggest that Li ion transport inside the pores of Cu-MOF-74 is via a Grotthuss-like mechanism where the charge is transported by coordinated hopping of Li ions between the perchlorate groups. This single-ion electrolyte is versatile and has wide applications. When the single-ion electrolyte is used for Li‖Li symmetric cells and Li‖LiFePO4 full cells, Li dendrites are suppressed. As a result, an ultralong cycle life is achieved for both cells. In addition, when the single-ion electrolyte is assembled into Li‖LiMn2O4 batteries, the dissolution of Mn2+ into the electrolyte is suppressed even at elevated temperatures, and a long cycle life with improved capacity retention is achieved for Li‖LiMn2O4 batteries. Finally, when the single-ion electrolyte is applied to Li–O2 batteries, an improved cycle life with reduced overpotential is also achieved.

Lithium ion capacitors (LIC), which can bridge the gap between lithium ion batteries and supercapacitors by combining the merits of the two systems, are thus considered as some of the most promising energy storage devices. However, the imbalances in specific capacity, high-rate behavior, and cycling lifespan between the two electrodes make it a challenge to develop LICs with high energy density at high power density output along with long cycle life. Herein, a LIC consisting of a three-dimensional carbon modified LTSO (3DC@LTSO) anode and a lignin-derived activated carbon (LDAC) cathode is designed and fabricated. These two electrode materials with desirable electrochemical properties will much favorably offset the imbalances between the two electrodes. Moreover, a novel electrode-matching strategic approach, which will further offset the imbalance between the two electrodes, is developed. Thereby, the assembled LDAC//3DC@LTSO LIC cell shows a high energy density of 115.3 W h kg−1 at 163.5 W kg−1 and a high power density of 6560 W kg−1 at 60 W h kg−1, coupled with an excellent cycling lifespan of 90% capacity retention after 6000 cycles at a current density of 2.0 A g−1. These combined results are impressive in terms of obtaining high energy density and long cycling lifespan LICs.

The vital challenge in relation to layered Ni-rich cathodes is their pronounced structural degradation originating from cation mixing at high voltage, which causes serious electrode polarization and electrochemical deterioration. Herein, an overall structural modification strategy, which integrates a Li2GeO3 coating with gradient Ge-doping, was developed to improve the structural stability and create ordered diffusion channels in a layered Ni-rich cathode via interfacial fusion at high temperature. This effective strategy significantly enhances the reversible capacity retention, voltage stability and rate capability of the layered Ni-rich cathode at high voltage. We find that the Li2GeO3 coating inhibits interfacial side reactions to enhance the surface structural stability of the cathode materials. More importantly, the gradient Ge-doping plays a critical role in suppressing cation mixing to improve the ordered channels available for Li+ ion transport. The experimental observations, corroborated by first principle calculations, further reveal that Ge-doping not only alleviates structural degradation by increasing the phase transition energy barrier for layers to form spinel-like or rock-salt phases, but also facilitates fast Li+ diffusion kinetics via reducing the diffusion barrier. Our work provides a design idea for stabilizing the surface/bulk structure of advanced cathodes for high-performance Li-ion batteries.

Lithium metal has been considered as a promising anode material for a long time because of its inherent high capacity and low potential. However, dendrite formation upon cycling hinders its application. Herein, a nano-Cu-embedded porous carbon (Cu@carbon) is synthesized by a simple heat treatment of a Cu–organic framework, and is then applied as a host for Li plating/stripping. It is found that the nano-Cu particles are uniformly embedded in the bulk and surface of the carbon, integrating high conductivity and high surface area. DFT calculations and experimental data indicate that the CuCx formed at the interface can serve as lithiophilic sites for Li nucleation and growth. As a result, the host material exhibits a dendrite-free Li plating/stripping. The half cell (Li‖Cu@carbon) shows a high coulombic efficiency of 99.3% over 200 cycles even with a high cycling capacity of 4 mA h cm−2, and the Li@Cu@carbon based symmetric cell can be cycled stably for over 2000 h at 1.0 mA cm−2. Furthermore, the corresponding Li-metal capacitor (activated carbon‖Li@Cu@carbon) and battery (LiFePO4‖Li@Cu@carbon) exhibit high cycling stability, with 80.1% capacity retention after 10 000 cycles (capacitor) and 94.7% capacity retention after 1000 cycles (battery). These achievements make our anode among the most stable Li anodes reported so far.

Manganese oxides/graphene composite material has become regarded as a highly promising electrode material for high-performance supercapacitors. However, some shortages such as low bonding strength and poor stability are faced to solve. In this work, carbon quantum dots serve as the bridge for connecting MnO2 and graphene, which contribute to synthesize the stable MnO2/carbon quantum dots/graphene composite aerogel. Due to the connection function of CQDs the stable combinations are formed between MnO2 nanoparticles and graphene nanosheets. Subsequently, the composite aerogel as-fabricated has the three-dimensional net structure, indicating a large specific surface area and abundant electron transport pathways. The MnO2/CQDs/GA electrode exhibits excellent electrochemical performance as compared to those of MnO2/GA and MnO2/G that are synthesized without the addition of CQDs. This composite electrode displays high specific capacitance of 721 F g-1 at 1 A g−1, good rate capability of 89.2% capacitance retention at 20 A g−1 and remarkable cycle stability of 92.3% capacitance retention after 10,000 at 10 A g−1. Moreover, the MnO2/CQDs/GA is quite stable and has preeminent electrochemical performance, which demonstrates the great potential for the development of high-performance supercapacitors.

Silicon is an ideal candidate anode material for Li-ion batteries (LIBs). However, it suffers from rapid capacity fading due to large volume expansion upon lithium insertion. Herein, we design and fabricate highly stable carbon coated porous Mg2Si intermetallic anode material using facile mechano-thermal technique followed by carbon coating using thermal vapour deposition (TVD), toluene as carbon source. The electrode exhibits an excellent first reversible capacity of 726 mAh g−1 at a rate of 100 mA g−1. More importantly, the electrode demonstrates high rate capability (380 mAh g−1 at high rate of 2 A g−1) as well as high cycle stability, with capacity retentions of 65% over 500 cycles. These improvements are attributable to both Mg supporting medium and the uniform carbon coating, which can effectively increase the conductivity and electronic contact of the active material and protects large volume alterations during the electrochemical cycling process.

An organometallic compound of ferrocene is first investigated as a promising anode for lithium-ion batteries. The electrochemical properties of ferrocene are conducted by galvanostatic charge and discharge. The ferrocene anode exhibits a high reversible capacity and great cycling stability, as well as superior rate capability. The electrochemical reaction of ferrocene is semi-reversible and some metallic Fe remains in the electrode even after delithiation. The metallic Fe formed in electrode and the stable solid electrolyte interphase should be responsible for its excellent electrochemical performance.

The broad application of lithium–sulfur technology is far from viable unless the obstacles associated with the dissolution of the sulfur cathode and the dendrite-growth related battery failure arising from the use of a metallic lithium anode are addressed. Taking advantage of the highly soluble sulfur species, this work explores the possibility of using redox-active species with highly positive potential to couple with a sulfur anolyte for a redox flow battery. When paired with an aqueous bromide catholyte, a sulfur–bromine (S–Br2) battery with the desired metal-free characteristic is successfully demonstrated. The battery exhibits a cell voltage exceeding 1.8 V, a specific capacity of ∼1600 mA h g−1, coulombic efficiency approaching 100% and decent cycling efficiencies over 100 cycles. A full-liquid flow-through mode is able to be realized with a controlled depth of charge. Moreover, a high energy density can be expected with highly concentrated electrolytes, guaranteeing a promising sustainable energy storage technology candidate for both stationary and mobile applications.

Flexible Li–air batteries have been proposed as a potential power source for next-generation flexible electronics due to their super-high theoretical energy density. However, the safety problems derived from dendritic-deposition and high-activity of a Li anode and the leakage and volatilization of liquid electrolyte severely impede their practical application. Herein, we design a flexible belt-shaped Li–air battery with high stability and safety, which is constructed by using a reduced graphene oxide (rGO)/Li anode, gel polymer electrolyte containing LiI and 4 wt% SiO2 (4% SiO2–LiI-GPE). The rGO/Li anode shows lower mass density, better toughness and less dendrite growth compared with a pure Li anode. Additionally, 4% SiO2–LiI-GPE has a high ionic conductivity of 1.01 mS cm−1, flame-resistant polymer matrix, excellent protective effect on the Li anode and no-leakage properties. Furthermore, the synergy of the LiI and SiO2 additives promotes the decomposition of discharge products and improves the safety of the battery at the same time. As a result, this belt-shaped Li–air battery can steadily run for 100 cycles with a small average overpotential of ∼1.45 V in ambient air (relative humidity of 15%) under different mechanical deformations. Moreover, its voltage curves over operation could remain almost unchanged under a series of bending conditions.

The traditional oxygen reduction/evolution reaction (ORR/OER) catalysts are mainly noble metal-based materials, but their scarcity and instability impede their practical applications, especially in Zn–air batteries. Hence, identifying a bifunctional catalyst with low-cost and high-stability is very crucial for Zn–air batteries. Herein, we report a simple method to prepare core–shell-structured Co@Co3O4 nanoparticles encapsulated into N-doped carbon polyhedra by carbonization and controlled oxidation of metal–organic frameworks (MOFs), which are then applied as a bifunctional catalyst for Zn–air batteries. Using such a configuration, enhanced performances, including a high power density of ∼64 mW cm−2, a stable voltage profile over 80 h battery operation with four mechanical recharges, a small discharge/charge overpotential of ∼0.66 V and a long-life of 100 cycles for 200 h operation at 5 mA cm−2, have been achieved. These excellent performances can be attributed to abundant graphited carbon and CNTs, high N-doping, plentiful pores, the synergy between the semiconductive Co3O4-coating layer and the conductive Co bulk, and the uniform Co@Co3O4 nanoparticles in this catalyst which effectively improve electrical conductivity/ion transfer and further concertedly promote the catalytic activity towards the ORR/OER. Moreover, the belt-shaped polymer Zn–air battery with this catalyst also shows good electrochemical stability under different deformations.

As a high-voltage and earth-abundant element, in recent years, alluaudite, Na2+2xFe2−x(SO4)3, has been regarded as a highly promising cathode material of sodium ion batteries with higher energy density. However, the critical environmental sensitivity and limited conductivity of this kind of sulfate-based (SO42−) polyanionic material has led to its poor crystal stability and inferior intercalation ability. Herein, we report the design of nitrogen-doped graphene under low temperature conditions as an evolutionary modification approach to prepare the Na2+2xFe2−x(SO4)3; namely, an alluaudite sulfate Na2+2xFe2−x(SO4)3@N-rGO composite was prepared by a facile co-precipitation method assisted by the nitrogen-doped graphene. It is therefore surprising that the three-dimensional graphene-based network provides continuous electron pathways; thus, the Na2+2xFe2−x(SO4)3@N-rGO composite exhibits improved electronic conductivity and excellent sodium insertion capability, as well as the electrochemical performance. As a result, it delivers a reversible capacity of 93.2 mA h g−1 with average redox potential of 3.8 V (vs. Na+/Na) at 0.05C; when the discharge rate increased to 10C, it delivers 56.3 mA h g−1 and an amazing capacity retention of 83% is achieved after 400 cycles. On the other hand, the doped nitrogen species plays a huge role on improving the electron-donating ability of the graphene layer, which effectively protects the easily oxidized host material from deterioration, giving the material longer stability in a normal oxygen-containing atmosphere. We believe that this work may lead to a promising, low cost, suitable sodium ion battery material for next-generation large-scale energy storage devices.

The magnesium-metal battery, which consists of a cathode, a Mg-metal anode, and a nonaqueous electrolyte, is a safer and less expensive alternative to the popular Li-ion battery. However, the performance of Mg batteries is greatly limited by the low electrochemical oxidative stability of nonaqueous electrolytes, the slow Mg2+ diffusion into the cathode, and the irreversibility of Mg striping and plating on the Mg metal anode. Here, we report the first Mg-ion battery using a Mg2+ aqueous electrolyte, nickel hexacyanoferrate cathode, and polyimide anode. The operation depends on Mg2+ intercalation–deintercalation at the cathode and reversible enolization at the anode, accompanied by Mg2+ transport between cathode and anode. The cell exhibits a maximum cell voltage of 1.5 V and a supercapacitor-like high power, and it can be cycled 5000 times. This system points the way to improved Mg-based rechargeable batteries.

As a recent addition to the family of van der Waals layered crystals, indium selenide (InSe) possesses unique optoelectronic and photonic properties, enabling high-performance electronic devices for broad applications. Nevertheless, the lithium storage behavior of InSe flakes is thus largely unexplored due to its low electronic conductivity and challenges associated with its exfoliation. Here, we prepare few-layered InSe flakes through liquid-phase exfoliation of wet-chemistry-synthesized layered InSe single crystals, and percolate the flakes with carbon nanotube (CNT) networks in order to form flexible anodes to store lithium (Li). We demonstrate, with the support of CNTs, that exfoliated InSe flakes possess superior Li storage capacity to bulk InSe; the capacity increases over prolonged cycling up to 1224 mA h g−1 from 520 mA h g−1, coupled with excellent rate handling properties and long-term cycling stability. The operando X-ray diffraction results suggest that the alloying of indium with Li dominates the Li storage reactions. By combining with density-functional theory calculations and post-mortem analysis, we believe that the in situ formed indium gradually reduces the domain size, forming nanoclusters which allow the accommodation of 4 Li+ per atomic indium, and leading to extra capacity beyond the traditional theoretical value. This new “nanoscluster alloying” Li storage mechanism may inspire new architectures or methods to synthesize few-layered InSe, thereby presenting broad opportunities for high-performance Li-ion battery anode technologies.

The term supercapacitor (or ultracapacitor) is used to indicate an electrochemical capacitor capable of storing charge through a capacitive process occurring in the electrical double layer formed at the interface between an electronic conductor (i.e., the electrode) and an electrolytic solution (e.g., non-aqueous electrolyte). The increasing demand for improved electrochemical energy storage systems continually boosts research efforts toward new materials, configurations and production processes, both for batteries and supercapacitors. The development of hybrid devices (e.g., where one electrode stores charge through a faradaic process and the other through a non-faradaic process) has also exploited progress in both the battery and supercapacitor fields. However, not all investigated materials are promising or industry-relevant, contrary to the claims in many research works. For example, complications related to the upscaling of lab-scale experiments hamper the exploitation at industrial scale. For these reasons, it is essential to define the best-practice methods to obtain reasonable predictions for supercapacitor materials and device testing. Also, many battery electrode materials are explored as supercapacitor electrode materials. However, not all battery materials can be considered as candidate electrode materials for hybrid devices. Only those materials with a suitable crystal structure for high rate capability and good cycling stability are appropriate.

Garnet-type solid-state electrolyte (SSE) has attracted much attention due to its wide electrochemical window, high mechanical strength, and chemically compatible with lithium metal. Nonetheless, the high sintering temperature and poor ability to suppress lithium dendrite strongly limit its application. Herein, we report a simple aqueous method to prepare in-situ lithium rich anti-perovskites (LiRAPs) coated garnet SSEs, and successfully reduce the sintering temperature from 1200 °C to 350 °C. The composite SSEs deliver a higher ionic conductivity (3.67 × 10−4 vs. 1.20 × 10−4 S cm−1) and a better cycling stability (84.8% capacity retention after 200 cycles vs. short-circuit after 90 cycles) than the pristine garnet SSEs. Moreover, the composite SSEs exhibit an improved ability to suppress lithium dendrite (over 200 h working for Li symmetrical cell and 0.7 mA cm−2 critical current density). This work demonstrates that in-situ LiRAPs coating strategy can effectively reduce the sintering temperature and suppress the Li dendrite growth inside the garnet electrolyte.

Reducing the ratio of Negative/Positive ratio (N/P ratio) is critical to increase the energy density of Li metal batteries (LMBs). Typically, stable Li deposition with high Coulombic Efficiency (CE) can be easily achieved with ether-based electrolyte, but the low oxidation stability restrains its applications in batteries with high-voltage cathodes. Herein, we performed cryogenic electron microscopy (Cryo-EM), in-depth X-ray Photoelectron spectrum (XPS) and Atomic Force Microscopy (AFM) on the Solid Electrolyte Interphase (SEI) layer formed in carbonate-based electrolyte and ether-based electrolyte to probe the characteristics of good SEI layer and aimed to design good SEI layer in carbonate-based electrolyte by tuning the electrolyte composition. The results suggest that the organic composition in the SEI layer determine the CE of LMBs. Further theoretical calculation suggests the highly reactive nature of carbonate molecules with Li results in the organic-rich SEI layer with low elastic modulus. On the basis of these insights, we propose design methodology for an advanced SEI layer in carbonate electrolyte by tuning the electrolyte composition. The designed SEI exhibits multilayer structure with a dense inorganic inner layer. Consequently, a 4 V full cell was assembled and delivered a high energy density of 760 Wh/kg (calculated based on the weight of cathode and anode) with long cycle life of 200 cycles in carbonate electrolyte.

Although hard carbons holds the most promise as anodes for practical sodium-ion batteries, high cost and low initial coulomb efficiency (ICE) limit their commercial application. In the present work, we develop an efficient solvothermal stabilization method to fabricate hard carbon spheres with high carbon yield from the wheat starch precursor. As anode for sodium-ion batteries, the obtained samples deliver not only a high capacity above 300 mAh g−1, but also an enhanced initial coulombic efficiency up to 90% and long cycle stability. Furthermore, when coupled with Na0.9[Cu0.22Fe0.30Mn0.48]O2 as cathode electrode, the full cell exhibited a high ICE of 85%, an average voltage of 3.2V and excellent stability during 300 cycles charging and discharging. These desirable electrochemical performances, combined with the renewable precursor and efficient synthesis route, make the obtained hard carbon sphere a promising anode for practical material for sodium-ion batteries.

Polyimide/activated carbon (PI/AC) composites were prepared by in situ polymerization of 1,4,5,8-naphthalenete-tracarboxylic dianhydride (NTCDA) and ethylene diamine (EDA) on activated carbon with various mass ratios varying from 50:50 to 70:30. These composites were examined as anode materials in 5 M LiNO3 solution in the potential window from −0.75 to 0 V vs Ag/AgCl. With an optimal composition PI/AC 50:50 in mass ratio, the composite delivers a specific capacity of 87 mAh g–1 at a current density of 0.2 A g–1, and it also shows excellent cycling stability and rate capability. A sealed full cell containing a PI/AC composite anode and LiMn2O4 cathode delivers a specific capacity of 42 mAh g–1 and energy density of 51Wh kg1– (based on the total weight of both active materials) at a current density of 0.2 A g–1. The full cell exhibits good cycling stability with a specific capacity of 35 mAh g–1 after 450 cycles, corresponding to a capacity retention of 89%.

To date, anode materials for lithium-ion batteries (LIBs) have been dominated by carbonaceous materials, which have a low intercalation potential but easily allow lithium dendrites to form under high current density, leading to a safety risk. The other anode material, the “zero-strain” spinel-structured Li4Ti5O12, with a ∼1.5 V vs. Li+/Li intercalation potential, exhibits excellent cycling stability and avoids the issues of dendrite growth and Li plating. The low capacity and high voltage of Li4Ti5O12, however, result in low energy density. Herein, we report a new and environmentally friendly anode material, Li2TiSiO5, which delivers a capacity as high as 308 mA h g−1, with a working potential of 0.28 V vs. Li+/Li, and excellent cycling stability. The lithium-storage mechanism of this material is also proposed based on the combination of in situ synchrotron X-ray diffraction, neutron powder diffraction with Fourier density mapping, ex situ X-ray absorption near edge structure analysis, ex situ transmission electron microscopy, and density-functional theory calculations with the projector-augmented-wave formalism. The lithium-storage mechanism of this material is shown to involve a two-electron (Ti4+/Ti2+ redox) conversion reaction between TiO and Li4SiO4.

Sodium-ion batteries have been considered as promising alternatives to the current lithium-ion batteries owing to their low cost and abundant raw material. The major challenge of their practical implementation is the lack of favourable anode material. Spinel Li4Ti5O12 has been regarded as a potential anode material for its superior capability of sodium-ion storage and relatively appropriate operating voltage. However, the low intrinsic ionic and electronic conductivity of spinel Li4Ti5O12 still remains as its major drawback. Herein, carbon-coated Li4Ti5O12 nanoparticles have been synthesized through a solid-state reaction and a chemical vapour deposition method and used as an anode material for sodium-ion battery. The composite structure demonstrates excellent stability and an initial discharge specific capacity of 120.1 mA h g−1, which is maintained at 101.5 mA h g−1 after 500 cycles corresponding to 85% of capacity retention at a current density of 0.1 A g−1. In addition, a full cell was fabricated with carbon-coated Na3V2(PO4)3 as a positive electrode, which displayed discharge specific capacities of 138.5 mA h g−1 that was maintained at 114.7 mA h g−1 after 50 cycles at a current density of 0.05 A g−1, and the capacity retention was 82.8%. The results indicated that the Li4Ti5O12 nanoparticle with a carbon layer shows a promising electrochemical performance as anode materials in sodium-ion batteries.

Na3V2(PO4)3 (NVP) is considered a promising potential electrode material for both the cathode and anode in sodium ion batteries. Recently, flexible sodium ion batteries have attracted increased attention regarding their use as energy storage devices compatible with portable electronics, roll-up displays, implantable devices, and other applications. Here, a feasible strategy was adopted to prepare binder-free, mechanically robust, and paper-like carbon-coated NVP/reduced graphene oxide (NVP@C@rGO) electrodes. Combining the advantages of the large 2D rGO surface and nano-composite sandwich-like microstructure, the as-fabricated feasible NVP@C@rGO electrode demonstrated high reversible capacities and good rate capabilities both as a cathodic and as an anodic material. In addition to the half cell fabricated using a pure Na foil as the counter electrode, an interesting symmetric full cell constructed with NVP@C@rGO//NVP@C@rGO was systemically studied. The optimum design of the full cell exhibited good electrochemical performance, with 1.7 V as the output voltage plateau and a satisfactory capacity of 74.1 mA h g−1 at 0.5C. Up to 10C, this sodium full cell still exhibited stable capacity. Under arbitrary bending conditions, this flexible full cell can still exhibit a stable and safe electrochemical performance. This work may lead to a promising, low cost sodium full cell strategy for next-generation flexible energy storage devices.

Sodium iron phosphate (Na3Fe2(PO4)3) as cathode material for sodium-ion batteries has been synthesized through a simple method of a solid state reaction. It crystallizes in a monoclinic structure i...

Two different Li-rich nickel–cobalt–manganese-oxide (Li-rich NCM) active materials with the same nominal composition 0.5Li2MnO3:0.5Li(Ni1/3Co1/3Mn1/3)O2 but different pristine nano structure have been analyzed structurally and electrochemically in different cycling states. For structural characterization, transmission electron microscopy (TEM) and high resolution synchrotron powder diffraction (S-XRD) experiments were conducted. The changes in structure with increasing cycle number are correlated with characteristic features in the corresponding electrochemical dQ/dV-profiles that were obtained by galvanostatically cycling the two different active materials. The presented data demonstrates that structural changes upon cycling, e.g. LiMnO2 and spinel formation, strongly depend on the degree oxygen is involved in the reversible charge compensation for delithiation/lithiation. According to our data, firstly a twin-like environment with nanometer dimensions is formed within the R-3m matrix during the initial cycle, which then gradually transforms into a spinel-like structure with increasing cycle number. As another result, we can show that Li2MnO3 to LiMnO2 transformation is not directly dependent in the irreversible oxygen loss in the first cycle but more importantly on transition metal migration. A model is presented explaining the dependency of LiMnO2 and spinel formation on the ability of Li-rich active materials to include oxygen in the charge compensation process.

Correction for ‘Ruthenium oxide coated ordered mesoporous carbon nanofiber arrays: a highly bifunctional oxygen electrocatalyst for rechargeable Zn–air batteries’ by Ziyang Guo et al., J. Mater. Chem. A, 2016, 4, 6282–6289, DOI: 10.1039/C6TA02030E.

Rechargeable aqueous zinc ion batteries (ZIBs) are emerging as impressive candidates for renewable energy storage, benefiting from their cost-effectiveness, environmental benignancy, and intrinsic safety. Unfortunately, the further development of aqueous ZIBs is plagued by the free water–induced parasitic reactions, including inevitable hydrogen evolution reaction (HER) and corrosion issues. Herein, with the aim to reduce the reactivity of solvent water, an effective strategy is proposed to construct the H-bonding with free water by adding an ether-based additive. It is found that the suppressed HER and zinc corrosion can be achieved through the participation of the H-bonding. Meanwhile, the electrode/electrolyte interface is tuned by increasing the wettability as well, which contributes to enlarge the effective area of electrode reaction. Furthermore, the results demonstrate that the performance of ZIBs can be improved through enhancing the stability of Zn anode.

Hard carbon is now one of the most promising anode materials for sodium-ion batteries, but achieving high reversible capacity at low voltage plateau (0–0.1 V) is still a major challenge, which can actually enhances the operating voltage as well as the energy density when coupled with cathodes. In this work, a series of hard carbon spheres (HCS) with controlled architectures for sodium ion batteries (SIBs) are prepared by carbonizing synthetic phenolic resin over a wide temperature range from 900 to 2800 °C. HCS treated at 1900 °C (HCS-1900) has a pure hard carbon structure with appropriate graphitic interlayer distance (0.358 nm) and microcrystal size (La ~ 1.61 nm, Lc ≈ 3.07 nm). It delivers a reversible capacity of 295 mAh g−1 and an ultra-large capacity of 248.2 mAh g−1 (84% of the reversible capacity) at low-voltage plateau, in which an intercalation mechanism is proposed for Na ion storage. Exquisite differential scanning calorimetry (DSC) analysis suggests that soliated hard carbon has better thermal stability than that of metallic Na.

Electrolyte decomposition in lithium-ion batteries results in the formation of a solid-electrolyte interphase (SEI), and this layer plays an essential role in determining the stability and cyclability of the battery. Besides electrolyte, electrode also affects the SEI products. In this work, the SEI formation processes on Li2TiSiO5 electrode is investigated and compared with nickel electrode using ex situ X-ray photoelectron spectroscopy. Li2TiSiO5 is a recently discovered Li-ion battery anode that works at an optimum voltage (~0.28 V vs. Li+/Li) but suffers from low coulombic efficiency. The electrolyte selected is 1 M LiPF6 in ethylene carbonate:diethyl carbonate:dimethyl carbonate (1:1:1, volumetric). The SEI layer formed on the surface of Li2TiSiO5 is shown to consist of lithium carbonate (Li2CO3), lithium alkyl carbonates (ROCOOLi), and lithium fluoride (LiF), with Li2CO3 being the dominant component. Small amounts of ROCOOLi and LiF are mostly formed in the deep lithiation stages. The SEI layer formed on nickel electrode, in comparison, only contains inorganic Li2CO3. These results suggest that Li2TiSiO5 either catalyzes or participates in the SEI formation reaction. A proper coating or a change in composition of Li2TiSiO5 can modify the property of SEI.