1
Nanoionics for Energy Storage and Conversion: Materials and Technologies

Nawishta Jabeen1*, Adeela Naz2, Imtiaz Ahmad2 and Ahmad Hussain3

1Department of Physics, Fatima Jinnah Women University, Rawalpindi, Pakistan

2School of Materials Science and Engineering, Harbin Institute of Technology, Shenzhen City, China

3Department of Physics, The University of Lahore, Sargodha Campus, Sargodha, Pakistan

Abstract

In the domain of nano-electronics and energy storage applications, a crucial scientific development has been made due to nanophotonics, moletronics, and nanoionics. Nanoionics emphasizes on the performance of ions at the nanoscale level principally in solid-state materials. Nanoionics has gained importance in recent years in the field of energy storage and conversion specifically for fuel cells, supercapacitors, and batteries, relying on its ion's transportation, high energy and power densities and longer cycle life. They can be utilized as electrode materials or as electrolyte materials for energy storage devices. In nanoionics, the small nanoscale electrode with higher surface area will be beneficial for the storing of ions and will result to the significant enhancement of the energy and power densities. In recent years the focus has been devoted to the nanoionics related to miniaturized electronic and energy applications that are crucial for electric vehicles and portable electronics. This field of research is flourishing and providing the versatile objective oriented opportunities and solutions for the growing demand of advanced energy related to technological issues for numerous industries. Furthermore, there is still a lot of research required to comprehend the mechanism, ion migration, and coupled redox process deeply.

Keywords: Nanoionics, ions transportation, energy storage, electrolytes, electrodes, supercapacitor, battery

1.1 Introduction

Fossil fuels, which have limited supplies and will eventually run out globally, provide the majority of today's energy needs. It is anticipated that by 2050, there will be 10 billion people on the planet. So, a civilization based on batteries has the potential to partially solve the trilemma that arises from the global expansion in energy and food production, global economic growth, and environmental protection. Fossil fuels may be phased out much sooner if there remained the shortage of research on renewable devices for the environmental and economic solutions. It takes a synthetic, non-polluting fuel derived from renewable sources to ensure a sustainable energy system. Rechargeable batteries, supercapacitors, and fuel cells are examples of energy storage technologies that may improve electrical properties by reducing length scales to the nanoscale [1, 2]. Large grain boundaries and surface atoms that alter ions farther away and affect bulk properties are features of nanostructured materials that set them apart from polycrystalline ones [3-6]. The development of nanotechnology allows the creation of material structures over a wide range of length scales, allowing for modification of fundamental attributes and the manipulation of inaccessible constants by humans [7, 8]. The enormous success of the nano-electronics area has been largely attributed to the capacity to create multifunctional materials and devices that are suited to particular needs [9]. For many energy storage and conversion applications, including electrochemical capacitors, batteries, fuel cells, and blue energy harvesting, efficient ion storage and quick ion transport in nanoporous electrodes are essential [10]. Interfaces have a substantial impact on ionic transport features, which results in size effects and material density. Nanoionics play a similar role to nano-electronics and semiconductor physics, with the importance of nanostructured arrangements being similar. Stability is crucial for nanostructured arrangements, and metastable interfaces can be durable even at high-temperatures. There is a distinct difference between electrons and ions, influenced by various factors, as shown in Figure 1.1. Their unique behaviors highlight fundamental contrasts in charge, mass, and interaction.

Figure 1.1 Difference between electron and ion.

Research on the appliances, mechanisms, properties, methodologies, effects, and applications associated with ion transport in nano-confinement is referred to as "nano"-"ionics" research. It is important to note that the name and concept of nanoionics are not new. The term "nanoionics" and its concept were first used in 1992 [11]. Earlier, Maier and numerous other scientists put in a tremendous amount of work to shape this research area and significantly contributed to it [12-14]. Nanoionics, originally focused on solid-state nanoscale systems, now encompasses ion transport and storage phenomena in liquids. Nanostructured conductors, such as nanocrystalline ceramics, nanoscale films, heterostructures, and nanocomposites, have distinct features and are being explored more and more for energy storage and transfer [15].

Figure 1.2 Ions demonstrate various exclusive benefits as compared to electrons for energy and information storage applications.

For instance, solid-state nanostructured materials should not be the only materials of choice. Similar to this, the use of nanoionics may extend beyond the usual electrochemistry-related areas to include activities like the transfer of energy and information. In the dynamic realm of technological evolution, nanoelectronics and nanoionics diverge in numerous fascinating ways, as vividly illustrated in Figure 1.2.

1.2 Nanoionics for Energy Storage

Already said, the upcoming generation of energy conversion and storage methods are projected to be significantly impacted by nanotechnology and nanostructured materials. A scientific and technological challenge that is unquestionably significant is the search for innovative, affordable, and ecologically acceptable alternatives to the present fuel cells, batteries, and super capacitors utilized in energy applications [16]. To create economically viable hybrid electric vehicles, for instance, it is vital to develop alternative technologies as lithium batteries, which are currently hitting their performance limits. In this chapter, current research into the development and manufacturing of energy devices that utilize nanoionics to enhance their functionality are discussed. Nanoionics have garnered significant attention in the field of energy storage applications, showcasing remarkable potential as illustrated in Figure 1.3.

Figure 1.3 Nanomaterials for energy storage applications.

1.2.1 Nanoionics for Batteries

Research on nanoionics is mostly relying onto improvement of the solid-state electrolytes that can conduct ions at the nanoscale. Solid-state electrolytes are of particular interest for next-generation lithium-ion batteries. Since nanoionic materials are better able to withstand the strain of ions intercalation and de-intercalation throughout charge and discharge cycles, it is anticipated that the implementation of nanostructured materials in batteries as electrode may cause in, a lengthier cycle life. Faster charging times may also be achieved using nanostructured electrodes because of their larger electrode/electrolyte contact area. Numerous studies have established that using Si-C-based nanocomposites or glasses containing SnO2 or different Sn-alloys as anodes enhances lithium battery cycling performance and keeps the batteries from shattering after a lot of cycles. It has also been demonstrated that employing TiO2 nanowires with just 40-60 nm in diameter, which can tolerate up to Li0.9ITiO2 (306 mAh/g) at 1.5-1.6 V vs Li+ (1M)/Li, improves capacity retention during cycling [17]. It is important to note that while working with nanoscale particles, electrochemical reaction pathways might be drastically different. Hematite, for instance, exhibits an irreversible phase transition in this situation.

Using large particles (1-2 m) prevents it from being used as an anode material; however, when using nanoparticles (20 nm), it exhibits amazing capabilities for Li-ions insertion [18]. Another way to boost electrode capacities is to utilize porous materials to enhance the electrodes' surface area. V2O5 aerogels have revealed to function improved as cathodes in lithium battery compared to polycrystalline non-porous powders of the similar arrangement [19, 20]. An additional example is the noticeably enhanced electrochemical responsiveness of carbon-coated nanoparticles containing phosphor-olivine LiFePO4, as this electrically insulating substance is prevented from forming inactive areas in the bulk form [21]. As a result of realizing that high electronic conductivity and high lithium diffusivity are not requirements for new electroactive materials for lithium batteries, but rather that these requirements can be met by using clever nanoscale designs, the search for new electroactive materials has been greatly accelerated.

1.2.2 Nanoionics for Supercapacitors

Traditional supercapacitors use liquid electrolytes, which can have limitations in terms of stability and performance. Nanostructured electrodes can also improve the performance of supercapacitors. Supercapacitors resemble batteries in certain ways, but they are made...