Research Progresses of Liquid Electrolytes in Lithium‐Ion Batteries

Abstract

batteries on the market are nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, lithium-ion batteries (LIBs), [1][2][3] etc. In addition to commercial lithium-ion batteries composed of graphite and LiCoO 2 , [4] batteries for emerging systems are also widely studied, such as silicon anode [5] and lithium sulfur batteries. [6] Presently, the widely-used secondary batteries in the industry are LIBs, [7][8][9][10][11][12][13] as shown in Figure 1.The electrolyte is an important part of the lithium-ion secondary battery. And it is the medium for realizing the migration of lithium ions between the positive and negative electrodes. To meet the ever-growing application requirements, the electrolytes can be divided into liquid electrolytes and solid-electrolytes, which can be inspired by each other. [14,15] Therefore, to improve the performance of the battery and develop new batteries, it is necessary to focus on the development and optimization of the electrolyte.The advantages of lithium-ion battery electrolytes are reflected in the large battery capacity and long cycle life, but there are still safety problems such as poor thermal stability. [16,17] Therefore, the secondary battery electrolyte is a subject worthy of in-depth study. It is of great practical significance to improve the performance of lithium-ion electrolytes by adding additives, changing solvents, lithium salts, etc. The main indicators for evaluating the performance of LIBs are safety, energy density, cycle life, and production cost, which are influenced by the properties of the electrolytes.

Ionic Transport through the Solid Electrolyte Interphase in Lithium-Ion Batteries: A Review from First-Principles Perspectives

“…Meanwhile, analysis of ionic transport through electrolytes and separators shall be accounted for in the encyclopedic understanding of ionic dynamics in LIBs. There are many review articles available on the ionic transport through separators including various solid and liquid electrolytes in LIBs. − …”

Effect of Fluoroethylene Carbonate Electrolyte Additives on the Electrochemical Performance of Nickel-Rich NCM Ternary Cathodes

“…The lithium-ion battery is one of the most successful energy storage systems in the past three decades, which has emerged as a cornerstone for our modern civilization. − The electrolyte between a cathode and an anode is an indispensable component in a lithium-ion battery. − It not only transports Li-ions in the cell during the charge/discharge process but also leads to the formation of complex interfaces on the electrodes (i.e., solid electrolyte interphase, SEI, or cathode electrolyte interphase, CEI) that could play an essential role in determining battery performances. Carbonate-based (e.g., ethylene carbonate/dimethyl carbonate, EC/DMC) electrolytes have achieved great success due to their excellent Li + transport property and good stability, which have become the mainstream commercial electrolytes. − However, the SEI formed with carbonate-based electrolytes is mainly composed of the carbonate ionic phase (e.g., lithium carbonate, Li 2 CO 3 ), organic lithium compounds (e.g., lithium ethylene decarbonate), and other organic species, which usually has poor stability during cycling. − …”

Effect of FEC electrolyte additive on the electrochemical performance of nickel-rich NCM ternary cathode

“…The electrolyte between a cathode and an anode is an indispensable component in a lithium-ion battery. [4][5][6][7][8] It not only transports Li-ions in the cell during the charge/discharge process, but also leads to the formation of complex interfaces on the electrodes (i.e., solid electrolyte interface, SEI, or cathode electrolyte interface, CEI) that could play an essential role in determining battery performances. Carbonate-based (e.g., ethylene carbonate/ dimethyl carbonate, EC/DMC) electrolytes have achieved great success due to their excellent Li + transport property and good stability, which have become the mainstream commercial electrolytes.…”

“…Carbonate-based (e.g., ethylene carbonate/ dimethyl carbonate, EC/DMC) electrolytes have achieved great success due to their excellent Li + transport property and good stability, which have become the mainstream commercial electrolytes. [7][8][9] However, the SEI formed with carbonate-based electrolytes is mainly composed of carbonate ionic phase (e.g., lithium carbonate, Li2CO3), organic lithium compounds (e.g., lithium ethylene decarbonate), and other organic species, which usually has poor stability. [10][11][12] To improve the properties of the electrode-electrolyte interphases, in particular, the anode surface, a widely used strategy is to add one or multiple electrolyte additives to form stable artificial SEI compositions that could suppress further side reactions between the electrolyte and anode as well as the growth of the notorious lithium dendrites.…”