Designing bifunctional oxygen electrocatalysts with high activity, lasting stability, and low-cost for rechargeable zinc-air batteries (RZABs) is a tough challenge. Herein, an advanced electrocatalyst is prepared by anchoring atomically dispersed Co atoms on N-doped graphene-like hierarchically porous carbon nanosheets (SA-Co-N₄-GCs) and thereby forming Co-N₄-C architecture. Its unique structure with excellent conductivity, large surface area, and three dimensional (3D) interconnected hierarchically porous architecture exposes not only more Co-N₄ active sites to accelerate the kinetics of both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), but also provides an efficient charge/mass transport environment to reduce diffusion barrier. Consequently, SA-Co-N₄-GCs exhibits excellent ORR/OER bifunctional activities and durability, surpassing noble-metal catalysts. Liquid RZABs using SA-Co-N₄-GCs cathodes display a high open-circuit voltage of 1.51 V, a remarkable power density of 149.3 mW·cm⁻², as well as excellent stability and rechargeability with faint increase in polarization even at a large depth of charge—discharge cycle with 16 h per cycle over an entire 600 h long-term test. Moreover, flexible quasi-solid-state RZABs with SA-Co-N₄-GCs cathodes also deliver a considerable power density of 124.5 mW·cm⁻², which is even higher than that of liquid batteries using noble-metal catalysts. This work has thrown new insight into development of high-performance and low-cost electrocatalysts for energy conversion and storage.

Silicon/carbon nanotube (Si/CNTs) nanocomposite is a promising anode material for lithium ion batteries (LIBs). Challenges related to the tricky synthesis process, as well as the weak interaction between Si and CNTs, hinder practical applications. To address these issues, a facile, one-step method to synthesize Si/CNTs nanocomposite by using silica (SiO₂) as a reactant via a magnesium reduction process was developed. In this synthesis, the heat released enables the as-obtained Si to react with CNTs in the interfacial region to form silicon carbide (SiC). By virtue of the unique structure composed of Si nanoparticles strongly anchored to conductive CNTs network with stable Si–C chemical bonding, the Si/SiC/CNT nanocomposite delivers a stable capacity of ~1100 mAh g⁻¹ and a capacity retention of about 83.8% after 200 cycles at a current density of 100 mA g⁻¹. Our studies may provide a convenient strategy for the preparation of the Si/C anode of LIBs.

The lithium-sulfur (Li-S) battery has received a lot of attention because it is characterized by high theoretical energy density (2,600 Wh/kg) and low cost. Though many works on the “shuttle effect” of polysulfide have been investigated, lithium metal anode is a more challenging problem, which leads to a short life, low coulombic efficiency, and safety issues related to dendrites. As a result, the amelioration of lithium metal anode is an important means to improve the performance of lithium sulfur battery. In this paper, improvement methods on lithium metal anode for lithium sulfur batteries, including adding electrolyte additives, using solid, and/or gel polymer electrolyte, modifying separators, applying a protective coating, and providing host materials for lithium deposition, are mainly reviewed. In addition, some challenging problems, and further promising directions are also pointed out for future research and development of lithium metal for Li-S batteries.

Based on recent reports of electrochemical catalysts for ZABs, we conclude that reconstruction of the structures of high-active carbon and metal composites during operation should be considered for optimization and reaching higher stability.

Metallic lithium is a promising next generation electrode material due to its ultrahigh specific capacity and lowest redox potential. However, its short cycling lifespan and safety hazards have hindered its practical application. To improve the cycling performance of lithium metal anodes, dendrite-free lithium deposition and a stable electrode–electrolyte interface are of vital importance. Here, we prepared a thin PMMA/PVDF gel coating using an electrospinning technique on a Cu substrate as the anode directly, which can not only homogenize lithium ion flux, promoting uniform lithium deposition, but can also alleviate the dramatic volume change in the lithium anode, improving the stability of the electrode interface. Owing to the excellent lithiophilic properties and high mechanical flexibility of the binary blend polymer coating, stable cycling for over 1400 h is achieved in a Li/Li symmetric cell using modified coating at 1 mA cm⁻² with a cycling capacity of 1 mA h cm⁻². The binary blend polymer coating with complementary properties prepared by this facile method provides a new insight for the lithium metal anode improvement.