In this work, phosphorus-doped graphene quantum dots (P-GQDs) with a high phosphorus doping content (>7 at%) are synthesized via an electrochemical approach. Sodium phytate (CHNaOP), a green food antioxidant additive, is used as the electrolyte for providing both a phosphorus source and an electrolysis environment. The obtained P-GQDs exhibit excellent scavenging activity of free radicals, such as hydroxyl radicals (˙OH) and 2,2-diphenyl-1-picrylhydrazyl (DPPH). Combined with Raman, FT-IR, and XPS spectral analyses, the reason for high phosphorus content and the mechanism of free radical scavenging of P-GQDs are investigated in our work.

With the rapid development of energy storage technology, solid‐state lithium batteries with high energy density, power density, and safety are considered as the ideal choice for the next generation of energy storage devices. Solid electrolytes have attracted considerable attention as key components of solid‐state batteries. Compared with inorganic solid electrolytes, solid polymer electrolytes have better flexibility, machinability, and more importantly, better contact with the electrode, and low interfacial impedance. However, its low ionic conductivity, narrow electrochemical stability window (ESW), and poor mechanical properties at room temperature limit its development and practical applications. In recent years, many studies have focused on improving the ionic conductivity of polymer electrolytes; however, few systematic studies and reviews have been conducted on their ESWs. A polymer electrolyte with wide electrochemical window will aid battery operation at a high voltage, which can effectively improve their energy density. Moreover, their stability toward lithium metal anode is also important. Therefore, this review summarizes the recent progress of solid polymer electrolytes on the ESW, discusses the factors affecting ESW of polymer electrolytes, and analyzes a strategy to broaden the window from the perspective of molecular interaction, polymer structural design, and interfacial tuning. The development trends of polymer electrolytes with wide electrochemical windows are also presented.

Due to its novel properties and unique utility, nitriles are attractive as an additive to lithium-ion battery electrolytes. However, when it is applied to high-voltage batteries, the effects and mechanisms are not clearly explained. In particular, we need to explore its mechanism. In this work, adiponitrile (ADN) has been employed as the additive in the electrolyte 1 M LiPF 6 -EC/DMC/EMC (1:1:1 by weight). The cycling tests for LiNi 0.5 Mn 1.5 O 4 half-cells after 150 cycles at 1 C (1 C = 147 mA/g) from 3.5 to 5.0 V show that adding 1 wt % ADN into the electrolyte can improve the capacity retention of the battery from 69.9% to 84.4%. Moreover, the rate performance can also be significantly improved. Based on the EIS measurement, a little ADN can stabilize the interfacial impedance avoiding a possible increase during cycling. To further clarify its mechanism, XRD, SEM, XPS measurements, and DFT calculations have been conducted, which display that when adding it into the liquid electrolyte, the cathode particles maintain good spinel shape and the molecule groups of ADN-S tend to be oxidized primarily to form a very thin film on the cathode surface. All these results indicate that ADN has potential applications in high performance electrolytes for storage systems.

No abstract

No abstract