This is the accepted version of the paper.This version of the publication may differ from the final published version. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 2 Rechargeable lithium ion batteries (LIBs) have long been considered as the most effective energy-storage technology and dominated portable electronic market for over two decades. Permanent repository link1, 2 Based on the intercalation mechanism, state-of-the-art Li-ion technology can exhibit a theoretical specific energy of ~400 Wh/kg, such as LiCoO 2 /graphite system. 3 However, it is urgent to explore new chemistries and materials that can significantly increase the cell energy density, considering the future demand for electronic vehicles and large-scale energy storage plants. 4,5 Graphite, a widely used anode material for the current LIBs, has a theoretical capacity of only 372 mAh/g, given a fully intercalated LiC 6 compound, which is one of the limiting factors for achieving high energy density of the cell 6 . In order to overcome such technical bottleneck, considerable effort has been devoted to design and synthesise new anode materials with higher theoretical specific capacity, such as transition metal oxides (SnO 2 , Co 3 O 4 ,Fe 3 O 4 ), Sn and Si 7 . However, all these materials suffer from severe volume variation during charge-discharge cycling, which results in serious pulverisation of the electrodes, and thus, rapid capacity degradation. For instance, Si has a high specific capacity of 4200 mAh/g if fully lithiated to Li 4.4 Si, however, it also shows a large volume expansion up to 400%. Such volume expansion causes huge mechanical stress of the electrode, and therefore, severely limits the lifetime of Si anode. Although various strategies have been proposed to enhance the structural stability of Si-based materials, including carbon or polymer coating 8,9 , nano-structuring 10-12 and hierarchical hybridization, [13][14][15] it is still very challenge to overcome the issue of the inherent volume change of these materials during cycling.Transition metal dichalcogenides (TMD) MX 2 (M=Mo, Ti, V, and W, X=S or Se) 16,17 with the similar feature of layered structure as graphite could have great potential for alternative anode materials. In general, MX 2 has strong covalent bonds within layers and weak Van der Waals forces between layers, which provide ideal space for intercalation of lithium ions. For instance, MoS 2 has much larger spacing between neighboring layers (0.615 nm) than that of graphite (0.335 nm) and weak van der Waals forces between the layers, which, in principal, may make the Li + diffuse easier. However, certain electrochemical properties of MX 2 can only be achieved in their 1-D or 2-D nanostructured crystals because of the relatively high resistance for Li-ion transport in their bulk form. In addition, the electron conductivity of th...

The renewable energy sources with intermittent nature call for fast development of electrical energy storage (EES) devices for practical applications. [1] Over the past decades, lithium-ion batteries (LIBs) have pervaded our daily lives, ranging from portable electronics to large-scale EES systems. [2] However, the cost of rare lithium resources involving electrical grid and large-scale storage purposes have raised widespread concerns. In this regard, sodium-ion batteries (SIBs) are highly promising to meet these demands due to that sodium is practically inexhaustible and easily accessible around the globe. [3] However, the higher standard electrochemical potential of Na + /Na (−2.71 V versus SHE) than that of Li + / Li (−3.04 versus SHE) and the larger ion radius of Na + compared with Li + (1.02 Å versus 0.76 Å) mean that SIBs possess a lower energy density, and most conventional electrode materials of LIBs are not suitable for SIBs. Hence, it is of great significance to explore advanced electrode materials that could provide satisfactory specific capacities and rapid ion diffusion kinetics. So far, the development of the cathode materials for SIBs has progressed rapidly, including layered oxides [4] and polyanionic compounds. [5] As for the anodes, although hard carbon as a hotspot has been widely studied due to its high capacity and lower voltage platform, [6] the random adsorption sites and irregular channels for Na + migration lead to a relatively poor sodium-ion diffusion. 2D transition metal chalcogenides (TMCs) have been broadly reported as a kind of promising electrode materials for both LIBs and SIBs due to their open framework and unique electrochemical properties. [7,8] Among them, WS 2 as a typical 2D TMCs has a much larger interlayer spacing of 0.62 nm and weaker van der Waals interaction, which enables fast reversible Na + diffusion and avoids terrible volume expansion during Na + intercalation/deintercalation processes. [9] However, the terrible issue of pure WS 2 anode applied in SIBs is its low intrinsic electronic conductivity, significantly limiting the specific capacity, and rate performance. [10] Generally, the electrochemical properties of materials are strongly dependent on the conductivity of electrode materials as well as the diffusion rate of Na +. Thus, the scrupulous design and rational controllable synthesis of Engineering novel electrode materials with unique architectures has a significant impact on tuning the structural/electrochemical properties for boosting the performance of secondary battery systems. Herein, starting from well-organized WS 2 nanorods, an ingenious design of a one-step method is proposed to prepare a bimetallic sulfide composite with a coaxial carbon coating layer, simply enabled by ZIF-8 introduction. Rich sulfur vacancies and WS 2 /ZnS heterojunctions can be simultaneously developed, that significantly improve ionic and electronic diffusion kinetics. In addition, a homogeneous carbon protective layer around the surface of the composite guarantees an outstandi...

can provide a promising strategy for green usage of CO 2 from the atmosphere. [6][7][8][9] The concept of aprotic lithium-CO 2 battery is proposed, in which the mechanism is based on the electrochemical reaction, 4Li + + 3CO 2 + 4e -<=> 2Li 2 CO 3 + C (E o = 2.80 V vs Li/Li + ), composed of CO 2breathing electrode as cathodes, lithium metal as anodes, and lithium salt dissolved in aprotic solvent as electrolyte. [6,9,10] Although the specific pathway of CO 2 reduction reaction is still unclear, it is generally accepted that the reduction reaction proceeds through the general steps shown below [8,9,11,12] ) has been proved to form on the electrode at the beginning of discharge process by the in situ surface-enhanced Raman spectroscopy. [11] And the mechanism of the electroreduction of CO 2 in aprotic solvents has also been reported, in which the CO 2 is reduced to CO 2 by one-electron reaction, Aprotic Li-CO 2 batteries are a new class of green energy storage and conversion system, which can utilize the CO 2 from the atmosphere in an environmentally friendly way. However, the biggest problem of the existing Li-CO 2 batteries is that they suffer from high polarization and poor cycling performance, mainly caused by the insulating and insoluble discharge product, Li 2 CO 3 . Herein, this study reports the synthesis of wrinkled, ultrathin Ir nanosheets fully anchored on the surface of N-doped carbon nanofibers (Ir NSs-CNFs) as an efficient cathode for improving the performance of lithium-CO 2 batteries. The battery can be steadily discharged and charged at least for 400 cycles with a cut-off capacity of 1000 mAh g −1 at 500 mA g −1 . Meanwhile, the cathode can effectively reduce the charge overpotential by showing a charge termination voltage below 3.8 V at 100 mA g −1 , which is the smallest charge overpotential reported to date. The ex situ analysis of the intermediate products reveals that during the discharge process, Ir NSs-CNFs can greatly stabilize amorphous granular intermediate (probably Li 2 C 2 O 4 ) and delay its further transformation into thin plate-like Li 2 CO 3 , whereas during the charge process, it can make Li 2 CO 3 be easily and completely decomposed, which is the key in greatly improving its performance for lithium-CO 2 batteries. Lithium-CO 2 BatteriesThe energy shortage and environmental pollution are the severe challenges for achieving the sustainable development of the human society. [1,2] Unfortunately, the main energy resources in the present society are still fossil fuels, which undoubtedly are nonrenewable, and produce a mass of greenhouse gases, resulting in accelerating the global temperature rise. [3][4][5] How to capture and convert CO 2 into renewable energy in an environmentally friendly way is attracting more intensive attention.Recently, the lithium-CO 2 battery as an innovative energy storageThe ORCID identification number(s) for the author(s) of this article can be found under https://doi.

In nature, cellulose nanofibers form hierarchical structures across multiple length scales to achieve high-performance properties and different functionalities. Cellulose nanofibers, which are separated from plants or synthesized biologically, are being extensively investigated and processed into different materials owing to their good properties. The alignment of cellulose nanofibers is reported to significantly influence the performance of cellulose nanofiber-based materials. The alignment of cellulose nanofibers can bridge the nanoscale and macroscale, bringing enhanced nanoscale properties to high-performance macroscale materials. However, compared with extensive reviews on the alignment of cellulose nanocrystals, reviews focusing on cellulose nanofibers are seldom reported, possibly because of the challenge of aligning cellulose nanofibers. In this review, the alignment of cellulose nanofibers, including cellulose nanofibrils and bacterial cellulose, is extensively discussed from different aspects of the driving force, evaluation, strategies, properties, and applications. Future perspectives on challenges and opportunities in cellulose nanofiber alignment are also briefly highlighted.

Lithium oxalyldifluoroborate (LiODFB) has been investigated as an organic electrolyte additive to improve the cycling performance of Li-S batteries. Cell test results demonstrate that an appropriate amount of LiODFB added into the electrolyte leads to a high Coulombic efficiency. Analyses by energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and the density functional theory showed that LiODFB promotes the formation of a LiF-rich passivation layer on the lithium metal surface, which not only blocks the polysulfide shuttle, but also stabilizes the lithium surface.