Nanostructural design renders several breakthroughs for the construction of high-performance materials and devices including energy-storage systems. Although attempts made toward electrode engineering have improved the existing drawbacks, nanoengineering is still hindered by some issues. To achieve practical applications of lithium-sulfur (Li-S) batteries, it is difficult to attain a high areal capacity with stable cycling. Physical encapsulation via nanostructural design not only can resolve the issue of lithium polysulfide dissolution during the electrochemical cycling, but also can offer significant contact resistance, which in turn can decrease the kinetics, particularly at a high sulfur loading. Thus, we demonstrate an electrospun carbon nanofiber (CNF) matrix for a sulfur cathode. This simple design enables a high mass loading of 10.5 mg cm with a high specific capacity and stable cycling. The CNF-sulfur complex can deliver a high areal capacity of greater than 7 mAh cm, which is related to the excellent electrical conductivity of one-dimensional species. Moreover, we have observed that the reacted sulfur species have adhered well to the junction of the CNF network with specific wetting angles, which are induced by the cohesive force between the narrow gaps in the matrix that trapped the viscous polysulfides during cycling. The results of this study open new avenues for the design of high-areal-capacity Li-S batteries.

Lead-free piezoelectric 0.5(BaCa)TiO-0.5Ba(ZrTi)O (BCTZ) nanoparticles (NPs) composed of earth-abundant elements were adopted for use in a flexible composite-based piezoelectric energy harvester (PEH) that can convert mechanical deformation into electrical energy. The solid-state synthesized BCTZ NPs and silver nanowires (Ag NWs) chosen to reduce the toxicity of the filler materials were blended with a polydimethylsiloxane (PDMS) matrix to produce a piezoelectric nanocomposite (p-NC). The naturally flexible polymer-based p-NC layers were sandwiched between two conductive polyethylene terephthalate plastic substrates to achieve a flexible energy harvester. The BCTZ NP-based PEH effectively generated an output voltage peak of ∼15 V and a current signal of ∼0.8 μA without time-dependent degradation. This output was adequate to operate a liquid crystal display (LCD) and to turn on six blue light emitting diodes (LEDs).

Sodium ion batteries (NIBs) have become attractive promising alternatives to lithium ion batteries in a broad field of future energy storage applications. The development of high‐performance anode materials has become an essential factor and a great challenge toward satisfying the requirements for NIBs, advancement. This work is the first report on GeS2 nanocomposites uniformly distributed on reduced graphene oxide (rGO) as promising anode materials for NIBs prepared via a facile hydrothermal synthesis and a unique carbo‐thermal annealing. The results show that the GeS2/rGO hybrid anode yields a high reversible specific capacity of 805 mA h g−1 beyond the theoretical capacity, an excellent rate capability of 616 mA h g−1 at 5 A g−1, and a cycle retention of 89.4% after 100 cycles. A combined ex situ characterization study reveals that the electrochemically driven amorphization plays a key role in achieving efficient sodium storage by accommodating excess sodium ions in the electrode materials. Understanding the sequential conversion‐alloying reaction mechanism for GeS2/rGO hybrid anodes provides a new approach for developing high‐performance energy storage applications.

It is highly desirable to develop advanced electrode structures of lithium–sulfur (Li–S), which enable high energy density, long life, low cost, and environmental benignity. In particular, suppression of polysulfide (PS)-shuttle behavior that occurs during electrochemical reaction in Li–S batteries is the most important challenge for practical, large-scale applications. In this work, a natural-wood-derived polymer, lignosulfonate sodium salt (LSS), is employed as a binder material for Li–S, showing superior capacity and cycle retention because of its unique chemical structure. LSS with amphiphilic functional groups can easily disperse hydrophobic electrode components in water and effectively block PS dissolution by its electrostatic repulsion force. Moreover, with enhanced Li ionic conductivity, the rate capability of the S cathode is maintained at ∼661 mA h g–1 at a current rate of 1675 mA g–1 and stable areal capacity of ∼1.55 mA h cm–2 is obtained with pristine S active material.

Over the past decades, there has been tremendous progress to overcome the intrinsic issues of lithium metal batteries (LMBs). In particular, studies have shown that utilizing lithiophilic materials for LMBs...