Lithium-sulfur batteries (LSBs) show promise as commercial batteries for electric vehicles (EV), portable devices and grid storage due to its low cost and high theoretical energy density. For EV applications, the areal capacity of LSBs needs to reach ~6 mAh.cm -2 to compete with the state-of-the-art LIBs. However, currently the practical application of LSBs is a great challenge due to low sulfur loading, self-discharge and low sulfur utilization. As such, different strategies have been investigated to improve the feasibility of LSBs at high sulfur loading. Such approaches are critical, but few articles have focused on the areal capacity at high sulfur loading and long term cycling performance of LSBs. This review highlights the recent progress of LSBs at high sulfur loading to achieve feasible areal capacity and long-term cycling performance. Particular attention has been placed on the cathode and separators modifications, with a discussion around anode and electrolyte modifications to improve the LSB performance.

Different classes of coating materials with their functional groups and mechanism of interaction with PSs.

Recently, Sn 4 P 3 has emerged as a promising anode for sodium-ion batteries (SIBs) due to the high specific capacity. However, the use of Sn 4 P 3 has been impeded by capacity fade and an inferior rate performance. Herein, a biomimetic heterostructure is reported by using a simple hydrothermal reaction followed by thermal treatment. This bottlebrush-like structure consists of a stem-like carbon nanotube (CNT) as the electron expressway and mechanical support; fructus-like Sn 4 P 3 nanoparticles as the active material; and the permeable stoma-like thin carbon coating as the buffer layer. Having benefited from the biomimetic structure, a superior electrochemical performance is obtained in the SIBs. It exhibits a high capacity of 742 mA h g −1 after 150 cycles at 0.2C, and superior rate performance with 449 mA h g −1 at 2C after 500 cycles. Moreover, the sodium storage mechanism is confirmed by cyclic voltammetry and ex situ X-ray diffraction and transmission electron microscopy. In situ electrochemical impedance spectroscopy was adopted to analyze the reaction dynamics. This research represents a further step toward figuring out the inferior electrochemical performance of other metal phosphide materials.

Purpose This review paper aims to focus on recent advances of carbon nanotubes (CNTs) to produce gas sensors. Gas sensors are widely used for monitoring hazardous gas leakages and emissions in the industry, households and other areas. For better safety and a healthy environment, it is highly desirable to have gas sensors with higher accuracy and enhanced sensing features. Design/methodology/approach In this review, the authors focus on recent contributions of CNTs to the technology for developing different types of gas sensors. The design, fabrication process and sensing mechanism of each gas sensor are summarized, together with their advantages and disadvantages. Findings Nowadays, CNTs are well-known materials which have attracted a significant amount of attention owing to their excellent electrical, electronic and mechanical properties. On exposure to various gases, their properties allow the detection of gases using different methods. Therefore, over recent years, researchers have developed several different types of gas sensors along with other types of sensors for temperature, strain, pressure, etc. Originality/value The main purpose of this review is to introduce CNTs as candidates for future research in the field of gas sensing applications and to focus on current technical challenges associated with CNT-based gas sensors.

No abstract