Two-dimensional (2D) energy materials have outstanding physical and chemical properties in contrast to their bulk counterparts. This is particularly true for charge storage devices such as lithium-ion batteries and supercapacitors. Unfortunately, when directly applying these 2D nanostructured materials for energy storage, there is still a significant challenge as they may have serious self-restacking leading to decreased active surface areas and sluggish ion transport kinetics. Researchers have now developed an effective interlayer engineering strategy to improve sodium ion transport in 2D nanosheets via controlled organic intercalation.
Sodium-ion battery, as an emerging battery technology beyond lithium-ion battery, has attracted great research interests recent years. Sodium-ion batteries have a similar configuration and electrochemical reaction processes with lithium-ion batteries. But the Na resources are much more abundant and cost-effective than Li resources, which makes sodium-ion batteries highly promising as next-generation energy storage devices, especially for large-scale energy storage. However, the practical application of Na-ion batteries is still not currently realized.
Wearable energy harvesters are greatly attractive and receive intensive research efforts in recent years, aiming at powering various emerging flexible and wearable electronics to meet the requirements of smart fabrics, motion tracking and health monitoring. Researchers now have developed a coating based on cellulose-derived hydrophobic nanoparticles and demonstrated its application as a wearable water triboelectric generator that harvests energy from water flow. This innovative fabric-based TEG has self-cleaning and antifouling properties.
Graphene currently is the most studied material on the planet - this is especially true for charge storage and the results from many laboratories confirm its potential to change today's energy-storage landscape. Specifically, graphene could present several new features for energy-storage devices, such as smaller capacitors, completely flexible and even rollable energy-storage devices, transparent batteries, and high-capacity and fast-charging devices.
Developing highly active electrocatalysts for photoelectrochemical water splitting is critical to bringing solar/electrical-to-hydrogen energy conversion processes into reality. Researchers have developed a novel 3D hierarchical hybrid electrocatalyst grown on electrochemically exfoliated graphene. The researchers then further integrated the hybrid nanosheets with a macroporous silicon photocathode, and the results show that it can enable highly active solar-driven photoelectrochemical water splitting in both basic media and real river water.
With a focus on using eco-friendly materials such as fabrics worn in daily life (nylon, jeans, cotton, etc.), researchers have developed and demonstrated an innovative product for scavenging biomechanical energy. The team's Smart Mobile Pouch Triboelectric Nanogenerator (SMP-TENG) can generate electricity from lateral sliding and vertical contact and separation with freestanding fabrics; it also can serve as a self-powered emergency flashlight and self-powered pedometer.
Steam is important for desalination, hygiene systems, and sterilization; and in remote areas where the sun is the only source of energy, being able to generate steam with solar energy could be very useful. Researchers now have found that the mushroom structure can surprisingly benefit solar steam generation. The stipe of the mushroom can serve as efficient water supply path, meanwhile, due to the extreme small ratio of the areas of fibrous stipe and black pileus, only little heat (useless heat loss) conducted into water.
In new work, a research team has developed a general synthesis strategy by employing graphene oxide as a sacrificial template to prepare various 2D holey transition metal oxide (TMO) nanosheets, including mixed metal oxides and simple metal oxides. This approach is universal for the synthesis of various 2D holey TMO nanosheets including mixed transition-metal oxides and simple oxides. This unique holey structure can minimize the restacking of 2D nanosheets and provide more active sites for alkali-ion storage.