Materials Challenges Facing Electrical Energy Storage

Abstract

During the past two decades, the demand for the storage of electrical energy has mushroomed both for portable applications and for static applications. As storage and power demands have increased predominantly in the form of batteries, the system has evolved. However, the present electrochemical systems are too costly to penetrate major new markets, still higher performance is required, and environmentally acceptable materials are preferred. These limitations can be overcome only by major advances in new materials whose constituent elements must be available in large quantities in nature; nanomaterials appear to have a key role to play. New cathode materials with higher storage capacity are needed, as well as safer and lower cost anodes and stable electrolyte systems. Flywheels and pumped hydropower also have niche roles to play.

Porous nanoarchitectures of spinel-type transition metal oxides for electrochemical energy storage systems

“…This understanding might lead to a commercially viable hybrid capacitor that does not contain any noble metal. 172 As we discussed in this section, porous spinel structures have great potential as energy storage materials in this research field. The porous structures have several advantages for boosting electrochemical reactions by minimizing diffusion distances of active species and accelerating the kinetic processes.…”

Mesoporous silicon sponge as an anti-pulverization structure for high-performance lithium-ion battery anodes

“…I ncreasing demands for high energy density, long cycle life, and low-cost lithium (Li)-ion batteries in critical applications such as electrical vehicles and portable devices have stimulated extensive research interest in developing novel electrode materials 1,2 . Among all the candidates for anode materials, silicon (Si) has a theoretical specific capacity of B4,200 mAh g À 1 (Li 22 Si 5 ), B11 times of the theoretical specific capacity of the state-of-theart graphite anode, and it does not have the safety concern of lithium metal dendrite formation 3 .…”

Kinetics and fracture resistance of lithiated silicon nanostructure pairs controlled by their mechanical interaction

“…3c). The mean stresses at the interfaces in crystalline Si and Li x Si (s m Si and s LixSi m ) for a given extent of lithiation (t 1 /t 0 ) are calculated by equations (3)(4)(5)(6)(7)(8) as shown in Fig. 3d.…”

“…S ilicon (Si) has attracted great attention as a promising negative electrode material for Li-ion batteries due to its exceptional theoretical specific capacity of 3,578 mAh g À 1 for the Li 15 Si 4 phase at room temperature [1][2][3][4][5] . Despite these preeminent theoretical properties, conventional Si anodes face significant challenges due to the large volume changes that accompany lithiation.…”