Uniform Ultrasmall Manganese Monoxide Nanoparticle/Carbon Nanocomposite as a High-Performance Anode for Lithium Storage

Direct Synthesis of NaBH4 Nanoparticles from NaOCH3 for Hydrogen Storage

Hydrogen is regarded as a promising energy carrier to substitute fossil fuels. However, storing hydrogen with high density remains a challenge. NaBH4 is a potential hydrogen storage material due to its high gravimetric hydrogen density (10.8 mass%), but the hydrogen kinetic and thermodynamic properties of NaBH4 are poor against the application needs. Nanosizing is an effective strategy to improve the hydrogen properties of NaBH4. In this context, we report on the direct synthesis of NaBH4 nanoparticles (~6–260 nm) from the NaOCH3 precursor. The hydrogen desorption properties of such nanoparticles are reported as well as experimental conditions that lead to the synthesis of (Na2B12H12) free NaBH4 nanoparticles.

A Novel Calcium-Ion Battery Based on Dual-Carbon Configuration with High Working Voltage and Long Cycling Life

Rechargeable batteries based on multivalent cations (e.g., Mg2+ and Al3+) have attracted increased interest in recent years because of the merits of natural abundance, low cost, good chemical safety, and larger capacity. Among these batteries, the Ca-ion battery (CIB) shows attractive priority because Ca2+ has the closest reduction potential (-2.87 V vs standard hydrogen electrode (SHE)), to that of Li (-3.04 V vs SHE), enabling a wide voltage window for the full battery. However, most Ca-ion batteries have low working voltage (below 2 V), as well as poor cycling stability (less than 50 cycles). Here, a high-performance Ca-ion full battery with a novel dual-carbon configuration design with low-cost and environmentally friendly mesocarbon microbeads and expanded graphite as the anode and cathode, respectively, is reported. This Ca-ion-based dual-carbon battery (Ca-DCB) can work successfully in conventional carbonate electrolyte dissolving Ca(PF6)2, with a reversible discharge capacity of 66 mAh g-1 at a current rate of 2 C and a high working voltage of 4.6 V. Moreover, the Ca-DCB exhibits good cycling stability with a discharge capacity of 62 mAh g-1 after 300 cycles with a high capacity retention of 94%, which is the best performance of the reported CIBs, suggesting it is a promising candidate for next-generation energy storage devices.

A Novel Potassium-Ion-Based Dual-Ion Battery

In this work, combining both advantages of potassium-ion batteries and dual-ion batteries, a novel potassium-ion-based dual-ion battery (named as K-DIB) system is developed based on a potassium-ion electrolyte, using metal foil (Sn, Pb, K, or Na) as anode and expanded graphite as cathode. When using Sn foil as the anode, the K-DIB presents a high reversible capacity of 66 mAh g^-1 at a current density of 50 mA g^-1 over the voltage window of 3.0-5.0 V, and exhibits excellent long-term cycling performance with 93% capacity retention for 300 cycles. Moreover, as the Sn foil simultaneously acts as the anode material and the current collector, dead load and dead volume of the battery can be greatly reduced, thus the energy density of the K-DIB is further improved. It delivers a high energy density of 155 Wh kg^-1 at a power density of 116 W kg^-1 , which is comparable with commercial lithium-ion batteries. Thus, with the advantages of environmentally friendly, cost effective, and high energy density, this K-DIB shows attractive potential for future energy storage application.

Facile synthesis of porous manganese oxide/carbon composite nanowires for energy storage

We proposed a facile in situ fabrication strategy for preparing porous MnO/C composite nanowires by one-step carbonization of manganese-based coordination polymer nanowires precursor.

Carbon-Coated Porous Aluminum Foil Anode for High-Rate, Long-Term Cycling Stability, and High Energy Density Dual-Ion Batteries

A 3D porous Al foil coated with a uniform carbon layer (pAl/C) is prepared and used as the anode and current collector in a dual-ion battery (DIB). The pAl/C-graphite DIB demonstrates superior cycling stability and high rate performance, achieving a highly reversible capacity of 93 mAh g^-1 after 1000 cycles at 2 C over the voltage range of 3.0-4.95 V. In addition, the DIB could achieve an energy density of ≈204 Wh kg^-1 at a high power density of 3084 W kg^-1 .

Interconnected Nanoflake Network Derived from a Natural Resource for High-Performance Lithium-Ion Batteries

Numerous natural resources have a highly interconnected network with developed porous structure, so enabling directional and fast matrix transport. Such structures are appealing for the design of efficient anode materials for lithium-ion batteries, although they can be challenging to prepare. Inspired by nature, a novel synthesis route from biomass is proposed by using readily available auricularia as retractable support and carbon coating precursor to soak up metal salt solution. Using the swelling properties of the auricularia with the complexation of metal ions, a nitrogen-containing MnO@C nanoflake network has been easily synthesized with fast electrochemical reaction dynamics and a superior lithium storage performance. A subsequent carbonization results in the in situ synthesis of MnO nanoparticles throughout the porous carbon flake network. When evaluated as an anode material for lithium-ion batteries, an excellent reversible capacity is achieved of 868 mA h g^-1 at 0.2 A g^-1 over 300 cycles and 668 mA h g^-1 at 1 A g^-1 over 500 cycles, indicating a high tolerance to the volume expansion. The approach investigated opens up new avenues for the design of high performance electrodes with highly cross-linked nanoflake structures, which may have great application prospects.