Facile Fabrication of Polymer Electrolytes via Lithium Salt-Accelerated Thiol-Michael Addition for Lithium-Ion Batteries

Click Chemistry in Lithium-Metal Batteries

Lithium-metal batteries (LMBs) are considered the "holy grail" of the next-generation energy storage systems, and solid-state electrolytes (SSEs) are a kind of critical component assembled in LMBs. However, as one of the most important branches of SSEs, polymer-based electrolytes (PEs) possess several native drawbacks including insufficient ionic conductivity and so on. Click chemistry is a simple, efficient, regioselective, and stereoselective synthesis method, which can be used not only for preparing PEs with outstanding physical and chemical performances, but also for optimizing the stability of solid electrolyte interphase (SEI) layer and elevate the cycling properties of LMBs effectively. Here it is primarily focused on evaluating the merits of click chemistry, summarizing its existing challenges and outlining its increasing role for the designing and fabrication of advanced PEs. The fundamental requirements for reconstructing artificial SEI layer through click chemistry are also summarized, with the aim to offer a thorough comprehension and provide a strategic guidance for exploring the potentials of click chemistry in the field of LMBs.

Organosulfur Materials for Rechargeable Batteries: Structure, Mechanism, and Application

Lithium-ion batteries have received significant attention over the last decades due to the wide application of portable electronics and increasing deployment of electric vehicles. In order to further enhance the performance of the batteries and overcome the capacity limitations of inorganic electrode materials, it is imperative to explore new cathode and functional materials for rechargeable lithium batteries. Organosulfur materials containing sulfur-sulfur bonds as a kind of promising organic electrode materials have the advantages of high capacities, abundant resources, tunable structures, and environmental benignity. In addition, organosulfur materials have been widely used in almost every aspect of rechargeable batteries because of their multiple functionalities. This review aims to provide a comprehensive overview on the development of organosulfur materials including the synthesis and application as cathode materials, electrolyte additives, electrolytes, binders, active materials in lithium redox flow batteries, and other metal battery systems. We also give an in-depth analysis of structure-property-performance relationship of organosulfur materials, and guidance for the future development of organosulfur materials for next generation rechargeable lithium batteries and beyond.

Understanding the effect of liquid crystal content on the phase behavior and mechanical properties of liquid crystal elastomers

Liquid crystal elastomers are stimuli-responsive, shape-shifting materials. They typically require high temperatures for actuation which prohibits their use in many applications, such as biomedical devices. In this work, we demonstrate a simple and general approach to tune the order-to-disorder transition temperature (T_ODT) or nematic-to-isotropic transition temperature (T_NI) of LCEs through variation of the overall liquid crystal mass content. We demonstrate reduction of the T_NI in nematic LCEs through the incorporation of non-mesogenic linkers or the addition of lithium salts, and show that the T_NI varies linearly with liquid crystal mass content over a broad range, approximately 50 °C. We also analyze data from prior reports that include three different mesogens, different network linking chemistries, and different alignment strategies, and show that the linear trend in T_ODT with liquid crystal mass content also holds for these systems. Finally, we demonstrate a simple approach to quantifying the maximum actuation strain through measurement of the soft elastic plateau and demonstrate applications of nematic LCEs with low T_ODTs, including the first body-responsive LCE that curls around a human finger due to body heat, and a fluidic channel that directionally pumps liquid when heated.

Lithium Salt-Induced In-Situ Polymerizations Enable Double Network Polymer Electrolytes

Structural design is an intriguing strategy to improve the physical and electrochemical performance of polymer electrolytes (PEs) for lithium-ion batteries. However, the complex synthetic process and introduction of non-electrolyte composition severely limit the development and practical application of PEs. Here we report a facile method for the fabrication of a double network polymer electrolyte (DN-PE) through combining the lithium salt-accelerated thiol-Michael addition and lithium salt-catalyzed radical polymerization. By adjusting the reaction temperature, the double network with the crosslinking structure could be in-situ formed step by step at room temperature and 80 °C. Notably, using lithium salt as the accelerator and catalyst avoids the addition of extra species and the related side reactions in the electrolyte system. Compared with single network polymer electrolyte (SN-PE), DN-PE has a distinctly improved mechanical strength and a better interfacial compatibility with the electrode, which leads to a stable cycling of the symmetric Li|DN-PE|Li cell over 1000 h at a current density of 0.05 mA cm^-2 . In addition, the Li|DN-PE|LiFePO₄ cell shows a high discharge specific capacity of 150.3 mAh g^-1 at 0.1 C and coulomb efficiency of 99%. This article is protected by copyright. All rights reserved.