MoS 2 Nanosheets Anchored on Melamine‐Sponges‐Derived Nitrogen‐Doped Carbon Microtubes as Anode for High‐Rate Sodium‐Ion Batteries

Influence of junction resistance on spatiotemporal dynamics and reservoir computing performance arising from an SWNT/POM 3D network formed via a scaffold template technique

For scientists in numerous fields, creating a physical device that can function like the human brain is an aspiration. It is believed that we may achieve brain-like spatiotemporal information processing by fabricating an in materio reservoir computing (RC) device because of a complex random network topology with nonlinear dynamics. One of the significant drawbacks of a two-dimensional physical reservoir system is the difficulty in controlling the network density. This work reports the use of a 3D porous template as a scaffold to fabricate a three-dimensional network of a single-walled carbon nanotube polyoxometalate nanocomposite. Although the three-dimensional system exhibits better nonlinear dynamics and spatiotemporal dynamics, and higher harmonics generation than a two-dimensional system, the results suggest a correlation between a higher number of resistive junctions and reservoir performance. We show that by increasing the spatial dimension of the device, the memory capacity improves, while the scale-free network exponent (γ) remains nearly unchanged. The three-dimensional device also displays improved performance in the well-known RC benchmark task of waveform generation. This study demonstrates the impact of an additional spatial dimension, network distribution and network density on in materio RC device performance and tries to shed some light on the reason behind such behavior.

Self-supporting network-structured MoS2/heteroatom-doped graphene as superior anode materials for sodium storage

Layered graphene and molybdenum disulfide have outstanding sodium ion storage properties that make them suitable for sodium-ion batteries (SIBs). However, the easy and large-scale preparation of graphene and molybdenum disulfide composites with structural stability and excellent performance face enormous challenges. In this study, a self-supporting network-structured MoS₂/heteroatom-doped graphene (MoS₂/NSGs-G) composite is prepared by a simple and exercisable electrochemical exfoliation followed by a hydrothermal route. In the composite, layered MoS₂ nanosheets and heteroatom-doped graphene nanosheets are intertwined with each other into self-supporting network architecture, which could hold back the aggregation of MoS₂ and graphene effectively. Moreover, the composite possesses enlarged interlayer spacing of graphene and MoS₂, which could contribute to an increase in the reaction sites and ion transport of the composite. Owing to these advantageous structural characteristics and the heteroatomic co-doping of nitrogen and sulfur, MoS₂/NSGs-G demonstrates greatly reversible sodium storage capacity. The measurements revealed that the reversible cycle capacity was 443.9 mA h g^-1 after 250 cycles at 0.5 A g^-1, and the rate capacity was 491.5, 490.5, 453.9, 418.1, 383.8, 333.1, and 294.4 mA h g^-1 at 0.1, 0.2, 0.5, 1, 2, 5 and 10 A g^-1, respectively. Furthermore, the MoS₂/NSGs-G sample displayed lower resistance, dominant pseudocapacitive contribution, and faster sodium ion interface kinetics characteristic. Therefore, this study provides an operable strategy to obtain high-performance anode materials, and MoS₂/NSGs-G with favorable structure and excellent cycle stability has great application potential for SIBs.

MoS2 encapsulated in three-dimensional hollow carbon frameworks for stable anode of sodium ion batteries

MoS₂ wrapped in nitrogen-doped three-dimensional hollow carbon frameworks is designed for improved sodium ion battery anode performance.

Titanium niobate (Ti2Nb10O29) anchored on nitrogen-doped carbon foams as flexible and self-supported anode for high-performance lithium ion batteries

Assembling active materials on flexible conductive matrixes for fabricating high-rate, self-supported and durable anodes is essential for the development of high-power flexible lithium-ion batteries. In this study, we report an efficient combinational strategy for producing hybrid composites (TNO@MCF) of Ti₂Nb₁₀O₂₉ (TNO) anchored on melamine carbon foam (MCF) via a hydrothermal method. The N-doped MCF not only showed good electronic conductivity and flexibility, but also improved the ion transport performance of the composites. The TNO@MCF electrode exhibited remarkably high rate capacities (327 mA h g^-1 at 1 C, and 205 mA h g^-1 at 40 C) and excellent cycling stability with a high capacity retention of 81.4% after 1000 cycles at 10 C. After 100 compression-rebound cycles, the TNO@MCF electrode showed a reversible capacity of 315 mA h g^-1 at 1 C and exhibited a capacity retention of 72.3% for 1000 cycles at 10 C. This compressible structure design could provide guidelines for manufacture of other flexible electrodes for energy storage devices.