Highly Stable Lithium Metal Batteries by Regulating the Lithium Nitrate Chemistry with a Modified Eutectic Electrolyte

Abstract

However, the further development of LIBs is restricted by the limited energy density, especially given the emerging large-scale energy storage applications. [2] Lithium metal is a competitive anode candidate with the merits of high theoretical capacity (3860 mAh g −1 ) and very low reduction potential (−3.04 V vs a standard hydrogen electrode). [3] Nonetheless, the problem of lithium dendrites and the stability of the electrolyte-electrode interphase still hinder its commercialization. [4] Furthermore, conventional carbonate electrolytes are flammable and can induce lithium dendrites, resulting in the production of "dead Li," which reduces the battery performance and raises safety concerns. [5] To address the severe dendrite issues in lithium metal batteries (LMBs), the formula design of the electrolyte has been proven to be an effective strategy. [6] As an additive, Lithium nitrate (LiNO 3 ) is generally recognized as an enhancer that forms robust solid electrolyte interphase (SEI) layers. [7] The NO 3 − derived reduction products, such as Li x N and LiN x O y , are good Li + conductors, thus accelerating the plating/ stripping behavior of Li + . [8] In addition, LiNO 3 binds to solvents or active substances in the electrolyte to strengthen the SEI layers and inhibit dendritic growth. [9] However, the strong interaction between Li + and NO 3 − cannot be broken in the conventional carbonate electrolyte, resulting in the extremely low solubility of LiNO 3 and hindering its application. [10] Although the ether electrolyte can dissolve a certain amount of LiNO 3 , its low operating voltage makes it difficult to meet the requirement of the LMB. Hence, it is essential to develop a safe and stable electrolyte with high LiNO 3 solubility to achieve better LMB. To date, various strategies have been reported to promote LiNO 3 dissolution in carbonate electrolytes such as using co-solvents, [11] slow release, [12] polymer-mediation, [13] and introducing solvent promoters. [14] However, these methods are characterized by complex processes and high costs. Therefore, there is an urgent need for a method that can facilitate LiNO 3 dissolution. Deep eutectic solvents (DESs), eutectic liquid mixtures of two or more solids formed by strong intermolecular forces, are new green solvents that have been widely utilized in extraction, organic synthesis, and electrochemistry. [15] DESs exist as liquids over a wide range of temperatures and offer excellent thermal stability. Moreover, Lithium nitrate is widely used as an additive in electrolytes to regulate the solid electrolyte interphase (SEI). However, the application of LiNO 3 in lithium metal batteries (LMBs) is limited by its extremely low solubility in conventional carbonate-based electrolytes. In this study, a non-flammable deep eutectic solvent (DES) with lithium bis(trifluoromethanesulfonyl)imide and N-methylacetamide (NMAC) as the main components is chosen as the LMB electrolyte. Using theoretical calculations and experiments, the strong interaction between NMAC and LiNO ...

Prelithiation: A Critical Strategy Towards Practical Application of High‐Energy‐Density Batteries

“…(2) appropriate delithiation/lithiation potential; (3) inexpensive and easy to synthesize; (4) safe and environmentally friendly; (5) compatible with existing lithium-ion battery production processes. [52,90,[148][149][150] In the following chapters, we summarize and discuss several representative cathode prelithiation additives, including sacrificial lithium-ion salts, binary lithium-rich compounds, metal/binary lithium-rich compound composites, ternary lithium-rich compounds. The specific capacities of different typical cathode prelithiation additives are summarized in Figure 10d.…”

“…[179] It is worth noting that Fan et al [40] The standard of ideal cathode prelithiation. [52,90,[148][149][150] d) The specific capacities of different cathode prelithium additives. [39,41,120, For the first time, Martin et al [180] used Li [181] Li 2 CO 3 /LiCoO 2 composites [182] were proposed as the cathode prelithiation materials; however, the proportion of inactive components such as catalysts, conductors are too high, which reduce the advantages of the high specific capacity.…”

“…b) Potential (V) requirement for ideal cathode additives. c) The standard of ideal cathode prelithiation [52,90,[148][149][150]. d) The specific capacities of different cathode prelithium additives [39,41,120,.…”

Recent progress in nonflammable electrolytes and cell design for safe Li-ion batteries

“…In addition, sacrificial additives can effectively improve the stability of the SEI and CEI, which in turn improve the stability of LIBs. Liang et al 109 introduced 4 wt% LiNO 3 as an additive into LiTFSI/N-methylacetamide (NMAC) electrolyte, in which the formation of a LiF, Li x N and LiN x O y enriched SEI on the Li anode enabled the NCM622‖Li full cell with 84% capacity retention for 600 cycles at 0.5C.…”

Recent progress on single-atom catalysts for lithium–air battery applications

“…[31][32][33][34] Therefore, various ''treatments'' towards these ''symptoms'' have been developed, such as the introduction of nanosized catalysts and lithium growth regulation sites. [35][36][37][38][39][40] To date, various kinds of cathode catalysts, such as particle-stacked catalysts, hollow-structured catalysts, MOF (metal-organic framework)-derived catalysts, fiber-assembled catalysts, and 3D-supported catalysts, are gradually emerging, which have their own disadvantages. 41 For example, hollow-structured catalysts have a large specific surface area and a high proportion of active sites, while MOFderived catalysts have the characteristics of heterogeneous and homogeneous electrocatalysis.…”