The Puzzles in Fast Charging of Li‐Ion Batteries

Abstract

Fast charging of Li‐ion cells faces two aspects of challenges, 1) accelerated capacity fade and 2) inferior charging capability. It is commonly believed that the former is due to Li plating and its resultant reactions with electrolyte at the graphite anode, which results in a loss in the inventory of Li+ ions and an increase in the cell’s impedance. While the latter is ascribed to the high voltage polarization in relation to the slow transport of Li+ ions between two electrodes. However, there are many other hidden facts that essentially affect the fast charging performances of Li‐ion cells. This commentary intends, from the view of materials, to uncover these hidden factors, including failure of the solid electrolyte interphase and exfoliation of the graphite structure at the anode, structural degradation of the Ni‐rich layered cathode materials, as well as the high solvation and desolvation activation energies of Li+ ions in the electrolyte. Meanwhile, some solutions to the fast‐charging problems of Li‐ion cells are proposed based on the understanding of these hidden factors.

An Experimental Method to Determine the Measurement Error of Reference Electrodes within Lithium‐Ion Batteries

“…For further understanding, the reader is referred to reviews and papers on these topics. [4,[19][20][21][22][23]…”

“…We will only cover these basics briefly. For further understanding, the reader is referred to reviews and papers on these topics [4,19–23] …”

Ethylene Glycol Intercalation Engineered Interplanar Spacing and Redox Activity of Ammonium Vanadate Nanoflowers as a High-Performance Cathode for Aqueous Zinc–Ion Batteries

“…In the past 30 years, lithium–ion batteries (LIBs) have been making up a huge market share of energy storage equipment in all aspects of daily life, on account of high energy densities and long lifespan. However, the sustainable use of lithium-ion batteries is limited by the shortage of lithium resources and the flammability of organic electrolytes. − Consequently, aqueous zinc–ion batteries (AZIBs) are likely to act as an alternative to LIBs for energy storage on a large scale on account of the abundant Zn resources, intrinsic safety, eco-friendliness, significant theoretical capacity (820 mAh g –1 ), and comparatively low oxidation–reduction potential (−0.76 V vs Standard Hydrogen Electrode). − On the way to the widespread application of AZIBs, it remains a challenge to design cathodes with the feature of high capacity, excellent rate performance, and good cycle stability. − …”

Emerging Multiscale Porous Anodes toward Fast Charging Lithium-Ion Batteries

“…49,52,74 However, previous reviews have paid little attention to the multiscale porous anodes design on the fast charging performance of LIBs. 15,21,26,75,17,25,33,76 Therefore, a timely summary of the multiscale design of porous fast charging anodes and an in-depth understanding of the influence of the pore design parameters on the rapid transport of Li + are of vital significance for guiding us in effectively designing fast charging LIBs.…”

“…Current LIBs with graphite anodes and metal oxide cathodes in liquid electrolytes cannot achieve the XFC goals without compromising battery performance and safety. Especially for the graphite anode, low operating potential and sluggish charge transfer result in polarization, electrolyte side reactions, and lithium metal plating at high charging rates. − Reversible lithium consumed during electroplating may reduce the anode porosity and reaction interface area. Further, if this process is accompanied by the formation and expansion of lithium dendrites, it may lead to an internal short circuit, resulting in safety accidents. − Therefore, the development of fast charging anodes has become a research hotspot in the past decade .…”