Exploring the use of oligomeric carbonates as porogens and ion-conductors in phase-separated structural electrolytes for Lithium-ion batteries

Phase-separated structural battery electrolytes (SBEs) have the potential to enhance the mechanical stability of the electrolyte while maintaining a high ion conduction. This can be achieved via polymerization-induced phase separation (PIPS), which creates a two-phase system with a liquid electrolyte percolating a mesoporous ther-moset. While previous studies have used commercially available liquid electrolytes, this study investigates the use of novel oligomeric carbonates to enhanced the safety of the SBEs. Increasing the carbonate chain length significantly enhances the thermal stability of the SBEs. Tuning the molecular structure of the liquid electrolyte has a significant effect on the PIPS process and SBE morphology. Using a combination of analyses on a series of wet and dried SBEs, the complex interplay between the phases is interpreted. When an increased pore size is achieved, it leads to a lower MacMullin number (NM). A conductivity of 2 x 10-5 S/cm with a NM=13 could be achieved, while maintaining a thermal stability up to 150 degrees C. The present study demonstrates a versatile approach to tailor this type of electrolyte

In Situ Polymerization Process: An Essential Design Tool for Lithium Polymer Batteries

Polymer electrolytes (PEs), a type of solid-state electrolytes (SSEs), have been in contention for nearly half a century to replace organic liquid electrolytes (LEs) that are used in state-of-the-art lithium-ion batteries (LIBs). They are envisaged to accelerate the industrial-scale production of safe, energy-dense, flexible, and thin lithium polymer batteries (LPBs). LPBs are expected to be widely employed for electric propulsion and other futuristic applications, such as flexible electronics and the Internet of Things (IoT). Even though several polymer architectures and chemistries have been attempted so far, PEs that can outperform LEs remain a real challenge. Apart from inadequate Li+-ion transport properties, challenges concerning the integration of PEs and the engineering of compatible, robust, and durable interfaces and interphases at both the electrodes of LPBs must be appropriately addressed. Recently, the in situ polymerization process has been widely employed as a robust fabrication tool for surpassing the intricacies related to the integration of PEs in LPBs. Hence, in this review, we focus on the in situ polymerization processes that employ various polymerization methods (e.g., free-radical polymerization, ionic polymerization, electropolymerization, condensation polymerization, etc.), functional monomers and oligomers (e.g., acrylate, methacrylate, allyl and vinyl ethers, epoxides, etc.), and PE integration strategies for the fabrication of lithium (ion and metal) polymer batteries (LIPBs and LMPBs). Additionally, this review also evaluates the approaches that have been developed until now to implement the in situ processing of LPBs from large-sized pouch cells to flexible-/printable-batteries and even microbatteries

An all-solid-state-supercapacitor possessing a non-aqueous gel polymer electrolyte prepared using a UV-assisted in situ polymerization strategy

International audienc

The role and the necessary features of electrolytes for microsupercapacitors

Numerous electrolytes based on aqueous and organic solvents, ionic liquids, inorganic materials, and polymeric matrices are used for microsupercapacitor (MSC) devices. Although solid-state electrolytes (SSEs) have been used in MSCs, most of the reports available in the literature are dominated by gel polymer electrolytes (GPEs) and liquid electrolytes. This chapter aims to shine a light on the various types of electrolytes that have been widely employed in the fabrication of MSCs. The chapter is segregated into different sections where the first section explains the use of inorganic solid electrolytes (ISEs) for MSCs followed by the next section that provides insights into liquid electrolytes. The subsequent sections are dedicated to the discussions on the significance of polymer electrolytes (PEs) and ionogels in MSC technology. The last section however summarizes the challenges and future perspectives of all-solid-state MSCs’ development

2D Layered Nanomaterials as Fillers in Polymer Composite Electrolytes for Lithium Batteries

Polymer composite electrolytes (PCEs), i.e., materials combining the disciplines of polymer chemistry, inorganic chemistry, and electrochemistry, have received tremendous attention within academia and industry for lithium-based battery applications. While PCEs often comprise 3D micro- or nanoparticles, this review thoroughly summarizes the prospects of 2D layered inorganic, organic, and hybrid nanomaterials as active (ion conductive) or passive (nonion conductive) fillers in PCEs. The synthetic inorganic nanofillers covered here include graphene oxide, boron nitride, transition metal chalcogenides, phosphorene, and MXenes. Furthermore, the use of naturally occurring 2D layered clay minerals, such as layered double hydroxides and silicates, in PCEs is also thoroughly detailed considering their impact on battery cell performance. Despite the dominance of 2D layered inorganic materials, their organic and hybrid counterparts, such as 2D covalent organic frameworks and 2D metal–organic frameworks are also identified as tuneable nanofillers for use in PCE. Hence, this review gives an overview of the plethora of options available for the selective development of both the 2D layered nanofillers and resulting PCEs, which can revolutionize the field of polymer-based solid-state electrolytes and their implementation in lithium and post-lithium batteries

High-Performance Flexible Solid-State Supercapacitor with an Extended Nanoregime Interface through in Situ Polymer Electrolyte Generation

Here, we report an efficient strategy by which a significantly enhanced electrode–electrolyte interface in an electrode for supercapacitor application could be accomplished by allowing in situ polymer gel electrolyte generation inside the nanopores of the electrodes. This unique and highly efficient strategy could be conceived by judiciously maintaining ultraviolet-triggered polymerization of a monomer mixture in the presence of a high-surface-area porous carbon. The method is very simple and scalable, and a prototype, flexible solid-state supercapacitor could even be demonstrated in an encapsulation-free condition by using the commercial-grade electrodes (thickness = 150 μm, area = 12 cm², and mass loading = 7.3 mg/cm²). This prototype device shows a capacitance of 130 F/g at a substantially reduced internal resistance of 0.5 Ω and a high capacitance retention of 84% after 32000 cycles. The present system is found to be clearly outperforming a similar system derived by using the conventional polymer electrolyte (PVA–H₃PO₄ as the electrolyte), which could display a capacitance of only 95 F/g, and this value falls to nearly 50% in just 5000 cycles. The superior performance in the present case is credited primarily to the excellent interface formation of the in situ generated polymer electrolyte inside the nanopores of the electrode. Further, the interpenetrated nature of the polymer also helps the device to show a low electron spin resonance and power rate and, most importantly, excellent shelf-life in the unsealed flexible conditions. Because the nature of the electrode–electrolyte interface is the major performance-determining factor in the case of many electrochemical energy storage/conversion systems, along with the supercapacitors, the developed process can also find applications in preparing electrodes for the devices such as lithium-ion batteries, metal–air batteries, polymer electrolyte membrane fuel cells, etc