Regulation of Cathode‐Electrolyte Interphase via Electrolyte Additives in Lithium Ion Batteries

Abstract

As the power supply of the prosperous new energy products, advanced lithium ion batteries (LIBs) are widely applied to portable energy equipment and large‐scale energy storage systems. To broaden the applicable range, considerable endeavours have been devoted towards improving the energy and power density of LIBs. However, the side reaction caused by the close contact between the electrode (particularly the cathode) and the electrolyte leads to capacity decay and structural degradation, which is a tricky problem to be solved. In order to overcome this obstacle, the researchers focused their attention on electrolyte additives. By adding additives to the electrolyte, the construction of a stable cathode‐electrolyte interphase (CEI) between the cathode and the electrolyte has been proven to competently elevate the overall electrochemical performance of LIBs. However, how to choose electrolyte additives that match different cathode systems ideally to achieve stable CEI layer construction and high‐performance LIBs is still in the stage of repeated experiments and exploration. This article specifically introduces the working mechanism of diverse electrolyte additives for forming a stable CEI layer and summarizes the latest research progress in the application of electrolyte additives for LIBs with diverse cathode materials. Finally, we tentatively set forth recommendations on the screening and customization of ideal additives required for the construction of robust CEI layer in LIBs. We believe this minireview will have a certain reference value for the design and construction of stable CEI layer to realize desirable performance of LIBs.

Face to Face at the Cathode Electrolyte Interphase: From Interface Features to Interphase Formation and Dynamics

“…The introduction of sacrificial electrolyte components (functional additives) is regarded as the most effective and cost affordable approach since their amount is usually kept ≤ 5% of the electrolyte composition. [ 86 ] An ideal CEI forming additive should fulfill a set of the following requirements: i) lower oxidation potential than state of the art (SOTA) electrolyte components, ii) compatibility with SOTA electrolyte components, iii) compatibility with the anode, and iv) enhancement of the ionic conductivity. [ 55,87,88 ] There are many compounds that can fulfill the requirements considering the compatibility with the SOTA electrolyte components and the negative electrode, however, a most crucial requirement refers to the lower oxidation potential compared to the SOTA electrolyte.…”

Constructing a Stable Interface Layer by Tailoring Solvation Chemistry in Carbonate Electrolytes for High‐Performance Lithium‐Metal Batteries

“…[ 15 ] Similarly, cathode electrolyte interface (CEI), which has not been investigated as much as the SEI, is also vulnerable to HF attack. [ 16 ] Therefore, reducing HF production is key to stabilizing the electrode/electrolyte interface layer in LiPF 6 ‐containing electrolytes.…”

Molecular Layer Deposition of Alucone Thin Film on LiCoO2 to Enable High Voltage Operation

“…To verify the importance of identity and composition of organic species in the CEI, [77–80] we have compared the rate performance of MLD coated LCO with Al 2 O 3 coated LCO, prepared by ALD (by alternating TMA and water precursors). Figure 6(d) represents the discharge capacities of coated and uncoated LCO as a function of C‐rate ranging from C/10 to 3 C (C/10, C/5, C/3, 0.8 C, 2 C, 3 C).…”