Details

Autor(en) / Beteiligte

• Ren, Yuxun
• Manthiram, Arumugam

Titel

A Dual‐Phase Electrolyte for High‐Energy Lithium–Sulfur Batteries

Ist Teil von

• Advanced energy materials, 2022-12, Vol.12 (46), p.n/a

Ort / Verlag

Weinheim: Wiley Subscription Services, Inc

Erscheinungsjahr

2022

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Dissolution of lithium polysulfides (LiPSs) is essential for fast cathode kinetics, but detrimental for anode stability, especially under lean electrolyte conditions. In this work, the phase separation phenomenon between solvents with different polarities (tetramethyl sulfone [TMS] and dibutyl ether [DBE]) is utilized to enable the design of a dual‐phase electrolyte. High‐polarity, high‐density TMS–lithium bis(trifluoromethanesulfonyl)imide–ammonium trifluoroacetate as the cathode electrolyte strongly solvates LiPSs, which propel the sulfur redox reaction. Moreover, the composite of DBE and a polymeric ion conductor serves as the anode electrolyte. The addition of DBE in the anode side effectively prevents the crossover of corrosive species (LiPSs and ammonia trifluoroacetate), enabling a significant improvement in Li‐metal anode stability. The electrode‐specific dual‐phase electrolyte design provides electrochemical performance superior to conventional electrolytes. Without additional electrode engineering, pouch cells assemble with the dual‐phase electrolyte cycle under a lean electrolyte (4 µL mg−1) and low‐Li‐excess condition (N/P = 3) for 120 cycles. Two immiscible liquid‐based electrolyte layers are applied for lithium–sulfur batteries. The sulfolane‐based cathode electrolyte layer promotes lithium polysulfide (LiPS) dissolution and conversion kinetics. The anode electrolyte layer containing low polarity dibutyl ether repels sulfone and LiPS, preventing anode corrosion.