Evaluation of the performance of N-doped graphene, synthesized by solvothermal method, as anode for Na-ion and Li-ion batteries

Silver Terephthalate (Ag2C8H4O4) Offering in-situ Formed Metal/Organic Nanocomposite as the Highly Efficient Organic Anode in Li-ion and Na-ion Batteries

Recently, lightweight, bendable and wearable electronic devices have been prevailing in the markets, there is a strong demand for high performance flexible electrode-active materials without binder and conductive agent that possess a high flexibility and energy capacity [1-3]. Li-ion batteries have received great attention as power sources for portable electronic devices, hybrid electric vehicles and energy storage system. However, considering the limited and uneven distribution of lithium minerals, room temperature Na-ion batteries have received growing attention because of their low cost and abundant supply. Na-ion batteries and Li-ion batteries share the same architecture of battery design. One of the major challenges for Na-ion batteries is to discover suitable electrode materials with high and stable sodium storage capabilities. We propose here a polypyrrole (PPy) thin film synthesized by an easy, inexpensive and scalable vapor phase polymerization (VPP) technique (Figure 1) [3]. As shown in Figure 1, the obtained PPy film shows smooth surface and continuously cross-linked structure. From the XRD and HR-TEM results (Figure 1), the obtained PPy film possesses well-ordered crystallized structure, which is helpful for Li+ and Na+charges transfer and storage. The as-derived free-standing PPy film anodes exhibit high rate performance and stable cycling life for both Li-ion batteries and Na-ion batteries. Detailed electrochemical properties and the structural transformation during charge-discharge processes of PPy film as anodes for Li-ion batteries and Na-ion batteries will be presented at the meeting. Acknowledgements: The authors gratefully acknowledge the support of the National Science Foundation of China (21403139, 51472161, 51472160), the Shanghai Pujiang Program (No. 14PJ1407100), the Key Program for the Fundamental Research of the Science and Technology Commission of Shanghai Municipality (15JC1490800, 12JC1406900) and the International Cooperation Program of the Science and Technology Commission of Shanghai Municipality (14520721700). We acknowledge the support of the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning (TP2014048) and the Hujiang Foundation of China (B14006).

Experimentally, black phosphorus (BP) displays a promising electrochemical performance as an anode for both Li ion and Na ion batteries. The feature of fast charge–discharge capability is very desirable for an anode material. We investigated the intercalation mechanism of a single Na and Li and the diffusion mechanism in BP by means of first-principles simulation. We found that a large tunnel forms because of the sliding of phosphorus interlayers with a single Na and Li intercalation and that the Na and Li diffusion within the tunnel along the a axis is very fast. This makes BP a competitive and promising anode for both Na ion and Li ion batteries. The different behaviors of Na and Li in BP are also discussed.

The one critical challenge for development of high capacity electrodes in Li-ion batteries is the cycle life. Extensive efforts have been devoted to improve the cycling stability of Si, Sn, P and their compound anodes. The one of the most successful technology is the use of nanostructured materials. We used different strategy to enhance the cycle life of these high capacity anodes. In this talk, we will summarize our efforts in extending the cycle stability of Si, Sn, P and SnP3 anodes for Li-ion and Na-ion batteries.

Through first-principles calculations, we successfully identified a two-dimensional layered nitridosilicate-MnSi2N4 in hexagonal structure, as a novel anode for lithium (Li) and sodium (Na) ion batteries. Phonon and molecular dynamics simulations manifest the favorable dynamic stability of MnSi2N4. The predicted material exhibits metallic behavior with high Young’s modulus of 457 GPa and aqueous insolubility. MnSi2N4 possesses low diffusion barrier for Li (0.32 eV) and Na (0.19 eV), as well as high storage capacity as an anode for Li (320 mAh g−1) and Na (160 mAh g−1) ion batteries, respectively. These properties, including excellent electronic conductivity, low diffusion barrier, and high storage capacity, enable MnSi2N4 a promising anode for Li and Na ion batteries.

Modern life is moving towards a mobile and sustainable energy economy, in which rechargeable batteries play an essential role as a power supply. The current battery of choice is Li ion battery that is dominating the market but faces great challenges for future use mainly due to the demand for higher capacities and target for cost reduction. Next-generation rechargeable batteries such as Li-O<sub>2</sub>, Li-S and Na ion batteries, which offers higher capacities and cost-effectiveness, are being intensively researched as potential solutions to meet the future energy storage demand. <br/>This thesis focuses on the search of high-performance anode materials for both Li and Na ion batteries, including metallic Li and Na, Si, MgH<sub>2</sub>, and black P and Sn<sub>4</sub>P<sub>3</sub> based composites. Various methods are involved to synthesize the active materials and electrodes in a cost-effective manner; and comprehensive characterization on the physico-chemical and electrochemical properties has been performed to provide fundamental understanding and insights into the electrochemical processes. This work has achieved long-lifespan and safe Li and Na metal anodes by suppressing the hazardous dendrite growth. The Si, P and MgH<sub>2</sub> anodes presented in this work also exhibit high and stable electrochemical performance for Li and Na ion storage. Notably, the Na ion uptake in Si and MgH<sub>2</sub> has been, for the first time, realized in experiments. This research shows great promise towards the commercial introduction of these anodes in next-generation high energy density Li and Na ion batteries.

Cobalt oxide (Co3O4)-based nanostructures have the potential as low-cost materials for lithium-ion (Li-ion) and sodium-ion (Na-ion) battery anodes with a theoretical capacity of 890 mAh/g. Here, we demonstrate a novel method for the production of Co3O4 nanoplatelets. This involves the growth of flower-like cobalt oxyhydroxide (CoOOH) nanostructures at a polarized liquid|liquid interface, followed by conversion to flower-like Co3O4 via calcination. Finally, sonication is used to break up the flower-like Co3O4 nanostructures into two-dimensional (2D) nanoplatelets with lateral sizes of 20-100 nm. Nanoplatelets of Co3O4 can be easily mixed with carbon nanotubes to create nanocomposite anodes, which can be used for Li-ion and Na-ion battery anodes without any additional binder or conductive additive. The resultant electrodes display impressive low-rate capacities (at 125 mA/g) of 1108 and 1083 mAh/g, for Li-ion and Na-ion anodes, respectively, and stable cycling ability over >200 cycles. Detailed quantitative rate analysis clearly shows that Li-ion-storing anodes charge roughly five times faster than Na-ion-storing anodes.

Synthesis of novel hard mesoporous carbons and their applications as anodes for Li and Na ion batteries

Nitrogen and sulfur dual-doped carbon films as flexible free-standing anodes for Li-ion and Na-ion batteries

Carbon‐oxide and carbon‐sulfide nanocomposites have attracted tremendous interest as the anode materials for Li and Na ion batteries. Such composites are fascinating as they often show synergistic effect compared to their singular components. Carbon nanomaterials are often used as the matrix due to their high conductivity, tensile strength, and chemical stability under the battery condition. Metal oxides and sulfides are often used as active material fillers because of their large capacity. Numerous works have shown that by taking one step further into fabricating nanocomposites with rational structure design, much better performance can be achieved. The present review aims to present and discuss the development of carbon‐based nanocomposite anodes in both Li ion batteries and Na ion batteries. The authors introduce the individual components in the composites, i.e., carbon matrices (e.g., carbon nanotube, graphene) and metal oxides/sulfides; followed by evaluating how advanced nanostructures benefit from the synergistic effect when put together. Particular attention is placed on strategies employed in fabricating such composites, with examples such as yolk–shell structure, layered‐by‐layered structure, and composite comprising one or more carbon matrices. Lastly, the authors conclude by highlighting challenges that still persist and their perspective on how to further develop the technologies.

The electrochemical and thermodynamic properties of MnO nanoparticle anchored N-doped porous carbon as the anode for Li-ion and Na-ion batteries are investigated.

Porous FeP/C composite nanofibers as high-performance anodes for Li-ion/Na-ion batteries

The intermittent nature of renewable energy sources, such as solar and wind, calls for sustainable electrical energy storage (EES) technologies for stationary applications. Li will be simply too rare for Li-ion batteries (LIBs) to be used for large-scale storage purposes. In contrast, Na-ion batteries (NIBs) are highly promising to meet the demand of grid-level storage because Na is truly earth abundant and ubiquitous around the globe. Furthermore, NIBs share a similar rocking-chair operation mechanism with LIBs, which potentially provides high reversibility and long cycling life. It would be most efficient to transfer knowledge learned on LIBs during the last three decades to the development of NIBs. Following this logic, rapid progress has been made in NIB cathode materials, where layered metal oxides and polyanionic compounds exhibit encouraging results. On the anode side, pure graphite as the standard anode for LIBs can only form NaC64 in NIBs if solvent co-intercalation does not occur due to the unfavorable thermodynamics. In fact, it was the utilization of a carbon anode in LIBs that enabled the commercial successes. Anodes of metal-ion batteries determine key characteristics, such as safety and cycling life; thus, it is indispensable to identify suitable anode materials for NIBs. In this Account, we review recent development on anode materials for NIBs. Due to the limited space, we will mainly discuss carbon-based and alloy-based anodes and highlight progress made in our groups in this field. We first present what is known about the failure mechanism of graphite anode in NIBs. We then go on to discuss studies on hard carbon anodes, alloy-type anodes, and organic anodes. Especially, the multiple functions of natural cellulose that is used as a low-cost carbon precursor for mass production and as a soft substrate for tin anodes are highlighted. The strategies of minimizing the surface area of carbon anodes for improving the first-cycle Coulombic efficiency are also outlined, where graphene oxide was employed as dehydration agent and 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) was used to unzip wood fiber. Furthermore, surface modification by atomic layer deposition technology is introduced, where we discover that a thin layer of Al2O3 can function to encapsulate Sn nanoparticles, leading to a much enhanced cycling performance. We also highlight recent work about the phosphorene/graphene anode, which outperformed other anodes in terms of capacity. The aromatic organic anode is also studied as anode with very high initial sodiation capacity. Furthermore, electrochemical intercalation of Na ions into reduced graphene oxide is applied for fabricating transparent conductors, demonstrating the great feasibility of Na ion intercalation for optical applications.

The editorial summarizes the contents of the special issue for energy storage in Advanced Functional Materials.

Na-ion batteries based on the inorganic BN nanocluster anodes: DFT studies