[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

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

Energy storage devices that can deliver high powers have many applications, including hybrid vehicles and renewable energy. Much research has focused on increasing the power output of lithium batteries by reducing lithium-ion diffusion distances, but outputs remain far below those of electrochemical capacitors and below the levels required for many applications. Here, we report an alternative approach based on the redox reactions of functional groups on the surfaces of carbon nanotubes. Layer-by-layer techniques are used to assemble an electrode that consists of additive-free, densely packed and functionalized multiwalled carbon nanotubes. The electrode, which is several micrometres thick, can store lithium up to a reversible gravimetric capacity of approximately 200 mA h g(-1)(electrode) while also delivering 100 kW kg(electrode)(-1) of power and providing lifetimes in excess of thousands of cycles, both of which are comparable to electrochemical capacitor electrodes. A device using the nanotube electrode as the positive electrode and lithium titanium oxide as a negative electrode had a gravimetric energy approximately 5 times higher than conventional electrochemical capacitors and power delivery approximately 10 times higher than conventional lithium-ion batteries.

High-Power Lithium Batteries from Functionalized Carbon Nanotube Electrodes

Conjugated microporous polymers (CMPs) are a unique class of materials that combine extended π-conjugation with a permanently microporous skeleton. Since their discovery in 2007, CMPs have become established as an important subclass of porous materials. A wide range of synthetic building blocks and network-forming reactions offers an enormous variety of CMPs with different properties and structures. This has allowed CMPs to be developed for gas adsorption and separations, chemical adsorption and encapsulation, heterogeneous catalysis, photoredox catalysis, light emittance, sensing, energy storage, biological applications, and solar fuels production. Here we review the progress of CMP research since its beginnings and offer an outlook for where these materials might be headed in the future. We also compare the prospect for CMPs against the growing range of conjugated crystalline covalent organic frameworks (COFs).

Advances in Conjugated Microporous Polymers.

Transition metal nitrides (TMNs), by virtue of their unique electronic structure, high electrical conductivity, superior chemical stability, and excellent mechanical robustness, have triggered tremendous research interest over the past decade, and showed great potential for electrochemical energy conversion and storage. However, bulk TMNs usually suffer from limited numbers of active sites and sluggish ionic kinetics, and eventually ordinary electrochemical performance. Designing nanostructured TMNs with tailored morphology and good dispersity has proved an effective strategy to address these issues, which provides a larger specific surface area, more abundant active sites, and shorter ion and mass transport distances over the bulk counterparts. Herein, the most up-to-date progress on TMN-based nanomaterials is comprehensively reviewed, focusing on geometric-structure design, electronic-structure engineering, and applications in electrochemical energy conversion and storage, including electrocatalysis, supercapacitors, and rechargeable batteries. Finally, we outline the future challenges of TMN-based nanomaterials and their possible research directions beyond electrochemical energy applications.

Transition metal nitrides for electrochemical energy applications.

The exploration of anode materials for lithium ion batteries (LIBs) or sodium ion batteries (SIBs) represents a grand technological challenge to meet the continuously increased demand for the high-performance energy storage market Here we report a facile and reliable synthetic strategy for in situ growth of few-layer MoS2 nanosheets on reduced graphene oxide (rGO) cross-linked hollow carbon spheres (HCS) with formation of three-dimensional (3D) network nanohybrids (MoS2-rGO/HCS) Systematic electrochemical studies demonstrate, as an anode of LIBs, the as-developed MoS2-rGO/HCS can deliver a reversible capacity of 1145 mAh g–1 after 100 cycles at 01 A g–1 and a revisible capacity of 753 mAh g–1 over 1000 cycles at 2 A g–1 For SIBs, the as-developed MoS2-rGO/HCS can also maintain a reversible capacity of 443 mAh g–1 at 1 A g–1 after 500 cycles The excellent electrochemical performance can be attributed to the 3D porous structures, in which the few-layer MoS2 nanosheets with expanded interlayers can prov

Three-Dimensional Network Architecture with Hybrid Nanocarbon Composites Supporting Few-Layer MoS2 for Lithium and Sodium Storage.

Fast Redox Kinetics in Bi‐Heteroatom Doped 3D Porous Carbon Nanosheets for High‐Performance Hybrid Potassium‐Ion Battery Capacitors

The development of electrode materials with the capability of balancing kinetics and capacity between a battery-type anode and capacitor-type cathode is still a grand challenge for potassium-ion hybrid capacitors (PIHCs). Herein, we report the design and synthesis of phosphorus/nitrogen co-doped hierarchical porous carbon nanofibers (PN-HPCNFs) that feature desirable one dimensional (1D) structure and favorable electrochemical properties for PIHC application. We demonstrated that the as-prepared PN-HPCNFs presented a highly attractive performance in terms of capacity or capacitance and durability as both the battery-type anode and capacitor-type cathode of PIHCs, which endows it with great potential for practical application in full PIHCs by delivering a high energy density of 191 W h kg−1 and a high power output of 7560 W kg−1 as well as an ultralong lifespan (82.3% capacity retention after 8000 cycles). Systematic characterization analysis and first-principle calculations demonstrated that the hierarchical pores in the 1D structure, heteroatom P/N co-doping, and enlarged interlayer graphite spacing in the APN-HPCNF contributed synergistically to the outstanding electrochemical performance of PIHCs.

Hierarchical porous carbon nanofibers for compatible anode and cathode of potassium-ion hybrid capacitor

Significant “breathing effect” calls for exploring efficient strategies to address the intrinsic issues of silicon anode of lithium-ion batteries (LIBs). We here report a controllable synthetic route to fabricate the silicon–carbon hybrids, in which porous silicon nanoparticles (p-SiNPs) are loaded in void carbon spheres by forming the yolk–shell p-SiNPs@hollow carbon (HC) nanohybrids tunable. A set of controlled experiments accompanying with systematic characterizations demonstrate that the void space and mass loading of Si can be adjusted in an effective way so that the nanostructure can be optimized with achieving improved electrochemical performance as anode of lithium-ion batteries (LIBs). The optimized p-SiNPs@HC nanohybrids show excellent performance as anode for Li-ion battery, delivering a capacity of more than 1400 mA h g–1 after 100 cycles at 0.2 A g–1 and 720 mA h g–1 at a high current density of 4 A g–1. The present work may provide us with an attractive and promising strategy for advancing S...

Tunable Synthesis of Yolk–Shell Porous Silicon@Carbon for Optimizing Si/C-Based Anode of Lithium-Ion Batteries

Reliable and General Route to Inverse Opal Structured Nanohybrids of Carbon‐Confined Transition Metal Sulfides Quantum Dots for High‐Performance Sodium Storage

Xiang Hu

Papers

Three-Dimensional Network Architecture with Hybrid Nanocarbon Composites Supporting Few-Layer MoS2 for Lithium and Sodium Storage.

Fast Redox Kinetics in Bi‐Heteroatom Doped 3D Porous Carbon Nanosheets for High‐Performance Hybrid Potassium‐Ion Battery Capacitors

Hierarchical porous carbon nanofibers for compatible anode and cathode of potassium-ion hybrid capacitor

Tunable Synthesis of Yolk–Shell Porous Silicon@Carbon for Optimizing Si/C-Based Anode of Lithium-Ion Batteries

Reliable and General Route to Inverse Opal Structured Nanohybrids of Carbon‐Confined Transition Metal Sulfides Quantum Dots for High‐Performance Sodium Storage