다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

Energy production and storage technologies have attracted a great deal of attention for day-to-day applications. In recent decades, advances in lithium-ion battery (LIB) technology have improved living conditions around the globe. LIBs are used in most mobile electronic devices as well as in zero-emission electronic vehicles. However, there are increasing concerns regarding load leveling of renewable energy sources and the smart grid as well as the sustainability of lithium sources due to their limited availability and consequent expected price increase. Therefore, whether LIBs alone can satisfy the rising demand for small- and/or mid-to-large-format energy storage applications remains unclear. To mitigate these issues, recent research has focused on alternative energy storage systems. Sodium-ion batteries (SIBs) are considered as the best candidate power sources because sodium is widely available and exhibits similar chemistry to that of LIBs; therefore, SIBs are promising next-generation alternatives. Recently, sodiated layer transition metal oxides, phosphates and organic compounds have been introduced as cathode materials for SIBs. Simultaneously, recent developments have been facilitated by the use of select carbonaceous materials, transition metal oxides (or sulfides), and intermetallic and organic compounds as anodes for SIBs. Apart from electrode materials, suitable electrolytes, additives, and binders are equally important for the development of practical SIBs. Despite developments in electrode materials and other components, there remain several challenges, including cell design and electrode balancing, in the application of sodium ion cells. In this article, we summarize and discuss current research on materials and propose future directions for SIBs. This will provide important insights into scientific and practical issues in the development of SIBs.

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Sodium-ion batteries: present and future

We developed two-step solution-phase reactions to form hybrid materials of Mn3O4 nanoparticles on reduced graphene oxide (RGO) sheets for lithium ion battery applications. Mn3O4 nanoparticles grown selectively on RGO sheets over free particle growth in solution allowed for the electrically insulating Mn3O4 nanoparticles wired up to a current collector through the underlying conducting graphene network. The Mn3O4 nanoparticles formed on RGO show a high specific capacity up to ~900mAh/g near its theoretical capacity with good rate capability and cycling stability, owing to the intimate interactions between the graphene substrates and the Mn3O4 nanoparticles grown atop. The Mn3O4/RGO hybrid could be a promising candidate material for high-capacity, low-cost, and environmentally friendly anode for lithium ion batteries. Our growth-on-graphene approach should offer a new technique for design and synthesis of battery electrodes based on highly insulating materials.

Mn3O4-Graphene Hybrid as a High Capacity Anode Material for Lithium Ion Batteries

Potassium-ion batteries are a promising alternative to lithium-ion batteries. However, it is challenging to achieve fast charging/discharging and long cycle life with the current electrode materials because of the sluggish potassiation kinetics. Here we report a soft carbon anode, namely highly nitrogen-doped carbon nanofibers, with superior rate capability and cyclability. The anode delivers reversible capacities of 248 mAh g–1 at 25 mA g–1 and 101 mAh g–1 at 20 A g–1, and retains 146 mAh g–1 at 2 A g–1 after 4000 cycles. Surface-dominated K-storage is verified by quantitative kinetics analysis and theoretical investigation. A full cell coupling the anode and Prussian blue cathode delivers a reversible capacity of 195 mAh g–1 at 0.2 A g–1. Considering the cost-effectiveness and material sustainability, our work may shed some light on searching for K-storage materials with high performance. The development of potassium ion batteries calls for cheap, sustainable, and high-performance electrode materials. Here, the authors report a highly nitrogen-doped soft carbon anode that exhibits superior rate capability and cyclability based on a surface dominated charge storage mechanism.

/pdf/highly-nitrogen-doped-carbon-nanofibers-with-superior-rate-xjhumaqn0i.pdf

Highly nitrogen doped carbon nanofibers with superior rate capability and cyclability for potassium ion batteries

The status of room-temperature potassium-ion batteries is reviewed in light of recent concerns regarding the rising cost of lithium and the fact that room-temperature sodium-ion batteries have yet to be commercialised thus far. Initial reports of potassium-ion cells appear promising given the infancy of the research area. This review presents not only an overview of the current potassium-ion battery literature, but also attempts to provide context by describing previous developments in lithium-ion and sodium-ion batteries and the electrochemical reaction mechanisms discovered thus far. Perspectives and directions on the techniques available to characterize newly developed battery materials are also provided based on our experience and knowledge from the literature. It is hoped that through this review, the potential of potassium-ion batteries as a competitive energy-storage technology will be realised, and the accessibility and available knowledge of the techniques required to develop the technology will be made apparent.

An Initial Review of the Status of Electrode Materials for Potassium-Ion Batteries

https://pubs.rsc.org/en/content/articlepdf/2016/cc/c6cc03649j

Tin-based composite anodes for potassium-ion batteries

Potassium-ion battery anode materials operating through the alloying–dealloying reaction mechanism

Potassium-ion batteries are a new class of high voltage electrochemical energy storage cells that may potentially complement or replace lithium-ion batteries in many applications. Graphite is considered as a prospective anode material for these batteries but its demonstrated capacity is only 270 mA h g−1. This manuscript studies a novel type of nanocomposite anodes based on black phosphorus as their main active component, with a much higher capacity in potassium-ion batteries. These anode materials are able to deliver a first cycle capacity as high as 617 mA h g−1, more than twice the capacity of graphite in potassium cells. Quick depotassiation is achievable in the electrodes under certain conditions. Based on the data of X-ray diffraction analysis, it is proposed that black phosphorus operates via an alloying–dealloying mechanism with potassium and the end product of the electrochemical transformation is a KP alloy (implying a theoretical capacity of 843 mA h g−1 for phosphorus in potassium cells). This work emphasizes the feasibility of potassium-ion battery anode materials with high gravimetric capacities, comparable with those of high capacity anode materials for lithium-ion and sodium-ion batteries.

High capacity potassium-ion battery anodes based on black phosphorus

https://pubs.rsc.org/en/content/articlepdf/2017/CC/C7CC03998K

Nanocrystalline SnS2 coated onto reduced graphene oxide: demonstrating the feasibility of a non-graphitic anode with sulfide chemistry for potassium-ion batteries

The hybridisation of Co3O4 and Fe2O3 nanoparticles dispersed in a super P carbon matrix is proposed as a favourable approach to improve the electrochemical performance (reversible capacity, cycling stability and rate capability) of the metal oxide electrodes in metal-ion batteries. Hybrid Co3O4–Fe2O3/C is prepared by a simple, cheap and easily scalable molten salt method combined with ball-milling and used in sodium-ion and potassium-ion batteries for the first time. The electrode exhibits excellent cycling stability and superior rate capability in sodium-ion cells with a capacity recovery of 440 mA h g−1 (93% retention) after 180 long-term cycles at 50–1000 mA g−1 and back to 50 mA g−1. In contrast, Co3O4–Fe2O3, Co3O4 and Fe2O3 electrodes display unsatisfactory electrochemical performance. The hybrid Co3O4–Fe2O3/C is also reactive with potassium and capable of delivering a reversible capacity of 220 mA h g−1 at 50 mA g−1 which is comparable with the most reported anode materials for potassium-ion batteries. The obtained results broaden the range of transition metal oxide-based hybrids as potential anodes for K-ion and Na-ion batteries, and suggest that further studies of these materials with potassium and sodium are worthwhile.

Irin Sultana

Papers

Tin-based composite anodes for potassium-ion batteries

Potassium-ion battery anode materials operating through the alloying–dealloying reaction mechanism

High capacity potassium-ion battery anodes based on black phosphorus

Nanocrystalline SnS2 coated onto reduced graphene oxide: demonstrating the feasibility of a non-graphitic anode with sulfide chemistry for potassium-ion batteries

K-ion and Na-ion storage performances of Co3O4–Fe2O3 nanoparticle-decorated super P carbon black prepared by a ball milling process