Aqua‐processable carbon quantum dot–assisted resilient polymer binder for advanced lithium‐sulfur batteries

Abstract

Lithium-sulfur batteries (LSBs) with outstanding theoretical capacity and environmentally friendly properties are regarded as next-generation energy storage devices. However, the shuttle effect of lithium polysulfide (LPS) limits the practical application of LSBs. Herein, we introduce an aqua-processable carbon quantum dot (CQD)-assisted resilient waterborne polyurethane (WPU) network binder for sulfur cathodes. WPU is a well-dispersed colloidal system with abundant polar groups that is suitable for regulating LPS shuttle effects. CQDs were prepared from WPU by hydrothermal treatment. The CQDs enabled facile electron/ion transport, enhanced the adsorption capability of LPS, and formed a robust network. Moreover, the chemical similarity between WPU and CQDs enabled the formation of a well-dispersed system, thereby affording optimal electrochemical performance. The WPU-CQD binder systems exhibited stable cycling performance at a high rate of 2C, with only 0.028% retention decay per cycle over 1000 cycles.

Highly Stable Potassium-Ion Battery Enabled by Nanoengineering of an Sb Anode

“…Nanoengineered Sb particles were synthesized using a simple and low-energy process, as illustrated in Figure . To prepare suitable CQDs with abundant functional groups for Sb composites, we used a simple hydrothermal method with green citric acid and urea. , During the formation of the CQDs decorated with Sb nanoparticles (Sb@CQD), CQDs act as the functional tuners and provide nucleation centers for Sb nanoparticles and well dispersed in the system because of the existence of polar functional groups on their surfaces . Therefore, the Sb can be generally grown on the surface of the CQDs to form nanocomposites.…”

“…Citric acid and urea were mixed in distilled water (25 mL) at a weight ratio of 2:1. Then, the solution was poured into a Teflon autoclave (Inexus, Inc., UK) and maintained at 160 °C for 6 h. , After being cooled to room temperature (RT), the solution was centrifuged at 8000 rpm for 15 min. Finally, the amino-conjugated CQDs dispersed in water appear to be a blue solution.…”

Electropolymerisation Technologies for Next-Generation Lithium–Sulphur Batteries

“…Various approaches for designing battery components have been introduced in LiSB research. Among them, cathode optimisation is the most effective method for addressing the main issues of LiSBs, i.e., LPS shuttles, low conductivity of active materials, and structural degradation of the cathode [20][21][22]. Various EP technologies have been introduced to facilitate cathode design.…”