High‐Concentration Additive and Triiodide/Iodide Redox Couple Stabilize Lithium Metal Anode and Rejuvenate the Inactive Lithium in Carbonate‐Based Electrolyte

Abstract

Carbonate-based electrolytes are incompatible with lithium (Li) metal anode because the generated solid electrolyte interphase (SEI) undergoes repeated breakage-repair, resulting in the accumulation of inactive Li including Li + compounds and electrically isolated dead Li 0 in the SEI. Therefore, exploiting a suitable strategy to construct a stable SEI while efficiently rejuvenating the inactive Li capacity is urgent and more thoughtful than just building a stereotyped SEI layer. Herein, an innovative strategy is proposed of high-concentration additive (HCA) of LiNO 3 inspired by (localized) high-concentration electrolyte and inactive Li restoration methodology via triiodide/iodide (I 3 − / I − ) redox couple to improve the compatibility of carbonate-based electrolytes. The HCA of LiNO 3 can maintain the cation-anion aggregates solvation structures in the carbonate-based bulk electrolyte and induce the in situ formation of superior-ionic-conductivity NO 3 − -derived SEI. Moreover, the reversible I 3 − / I − redox couple can further optimize the SEI and constantly rejuvenate the inactive Li including solvent/LiNO 3 -derived Li 2 O, a derivative has almost been acquiescent in LiNO 3 -additive electrolytes, and dead Li 0 into delithiated cathode. Consequently, epitaxy-like planar Li deposition, better reversibility, and higher capacity retention can be realized and are systematically verified by Li||Cu half cells, full cells with excess/limited Li (N/P ratio = 1.5) and anode-free lithium metal batteries.

Li Plating Regulation on Fast‐Charging Graphite Anodes by a Triglyme‐LiNO3 Synergistic Electrolyte Additive

“…Moreover, the G3 with relatively high desolvation energy encourages the formation of oligomeric ethers on the graphite surface, as previously reported. [22] Importantly, the interaction among the solvents in GLN-added electrolyte reduces the total solvent coordination numbers (Table S1), weakening the binding of the solvent to Li ion. This enables Li ion with a higher energy state and therefore a higher reduction tendency, as evidenced by the lower overpotential and fewer side reactions observed during Li plating (Fig- ure S7).…”

Recycling inactive lithium in lithium–sulfur batteries using organic polysulfide redox

“…Recycling inactive Li using redox, such as the redox of iodine redox (I 3 − /I − ), 10-methylphenothiazine, and 2,2,6,6-tetramethylpiperidinooxy, has been employed to reclaim inactive Li in Li metal batteries. [48][49][50][51] However, highly reactive soluble LiPSs in working Li-S batteries severely challenge the recycling of inactive Li. The reaction between soluble LiPSs and redox agents will deactivate the redox agents, while the sulfur redox reactions in Li-S batteries will also be affected in turn.…”

Reconstruction of Solid Electrolyte Interphase with SrI2 Reactivates Dead Li for Durable Anode‐Free Li‐Metal Batteries

“…Alternatively, reactive iodide-based substances (iodine@carbonized porous conidial powder@Li anode, [12] SnI 4 @Li anode, [13] LiI@Li anode, [14] and high-concentration-additive electrolyte with I 2 [15] ) are introduced to rejuvenate dead Li. However, iodide additive concentration in the electrolyte cannot realize the balance between electrolyte anti-oxidation stability and dead Li reactivation, but can only support AFLMBs with an extremely low capacity of 30 mAh g À 1 after 100 cycles.…”