Single‐Crystalline Cathodes for Advanced Li‐Ion Batteries: Progress and Challenges

Abstract

Single-crystalline cathodes are the most promising candidates for highenergy-density lithium-ion batteries (LIBs). Compared to their polycrystalline counterparts, single-crystalline cathodes have advantages over liquid-electrolyte-based LIBs in terms of cycle life, structural stability, thermal stability, safety, and storage but also have a potential application in solid-state LIBs. In this review, the development history and recent progress of single-crystalline cathodes are reviewed, focusing on properties, synthesis, challenges, solutions, and characterization. Synthesis of single-crystalline cathodes usually involves preparing precursors and subsequent calcination, which are summarized in the details. In the following sections, the development issues of single-crystalline cathodes, including kinetic limitations, interfacial side reactions, safety issues, reversible planar gliding and micro-cracking, and particle size distribution and agglomeration, are systematically analyzed, followed by current solutions and characterization techniques. Finally, this review is concluded with proposed research thrusts for the future development of singlecrystalline cathodes.

PrF3 Nanocoatings for Stabilizing Spinel LiNi0.5Mn1.5O4 Cathodes

“…Currently, there is a shortage of fossil energy in the world as well as serious environmental pollution. Therefore, lithium-ion batteries are widely used in the field of electric vehicles due to their environmental friendliness. − However, with the rapid development in the field of electric vehicles, the cost and energy density of lithium-ion batteries are also increasing. − The commercial development of layered metal oxides represented by LiCoO 2 is limited due to the high price and toxicity of Co, while the energy density of LiFeO 4 , LiMnO 4 , and other materials cannot meet the needs of a new generation of electric vehicles. − In contrast, the LiNi 0.5 Mn 1.5 O 4 (LNMO) material not only has low cost but also has an energy density of 650 Wh/kg and a discharge voltage platform of 4.7 V. − Therefore, LNMO has become a lithium battery cathode material with great potential and development prospects in the new era.…”

Morphology-Dependent Battery Performance of Ni-Rich Layered Cathodes: Single-Crystal versus Refined Polycrystal

“…Even if microcracks occur, numerous triple junctions and tortuous grain boundaries impede their propagation to the outer secondary particle surface. An alternative approach to suppress microcracking is the development of single-crystal cathodes. − Single-crystal cathodes, which do not comprise smaller grains and, as such, are free of grain boundaries, do not suffer from intergranular cracking. Moreover, their relatively low surface-to-volume ratio minimizes interfacial side reactions such as gas evolution, transition-metal dissolution, and parasitic electrolyte attack, resulting in superior thermal stability. − …”

“…In the case of cathodes comprising nanoscale elongated primary particles, their structures disperse mechanical stress to suppress microcracking but cannot completely eliminate microcracking during long-term cycling. In the case of single-crystal cathodes, their micrometer size results in much longer Li + diffusion paths, leading to poor reaction kinetics and low capacity. ,− The understanding of the more efficient approach, among the two, will aid the development of superior cathode materials. In this study, three different Ni-rich NCM cathodes (i.e., single-crystal, conventional, and refined polycrystalline Li­[Ni 0.9 Co 0.05 Mn 0.05 ]­O 2 (NCM90) cathodes) were synthesized to compare their electrochemical performance and capacity fading behaviors.…”

Recent progress in ZnCo2O4 and its composites for energy storage and conversion: a review

“…The LIBs, as the main power source, dominate the portable device market due to their high energy density, high output voltage, long life and environmentally friendly operation 31,44 . It is important to mention that many review works already published highlighting recent progress [45][46][47] , issues and challenges facing rechargeable LIBs 48 , as well as rechargeable sodium-ion batteries (SIBs) as potential alternatives to current LIBs 49 , which can be used to obtain more detailed information about these EESSs.…”