Manipulating Electric Double Layer Adsorption for Stable Solid‐Electrolyte Interphase in 2.3 Ah Zn‐Pouch Cells
Yu Wang, Bochun Liang, Jiaxiong Zhu, Geng Li, Qing Li, Ruquan Ye, Jun Fan, Chunyi Zhi
Abstract
Abstract Constructing a reliable solid‐electrolyte interphase (SEI) is imperative for enabling highly reversible zinc metal (Zn 0 ) electrodes. Contrary to conventional “bulk solvation” mechanism, we found the SEI structure is dominated by electric double layer (EDL) adsorption. We manipulate the EDL adsorption and Zn 2+ solvation with ether additives (i.e. 15‐crown‐5, 12‐crown‐4, and triglyme). The 12‐crown‐4 with medium adsorption on EDL leads to a layer‐structured SEI with inner inorganic ZnF x /ZnS x and outer organic C−O−C components. This structure endows SEI with high rigidness and strong toughness enabling the 100 cm 2 Zn||Zn pouch cell to exhibit a cumulative capacity of 4250 mAh cm −2 at areal‐capacity of 10 mAh cm −2 . More importantly, a 2.3 Ah Zn||Zn 0.25 V 2 O 5 ⋅ n H 2 O pouch cell delivers a recorded energy density of 104 Wh L cell −1 and runs for >70 days under the harsh conditions of low negative/positive electrode ratio (2.2 : 1), lean electrolyte (8 g Ah −1 ), and high‐areal‐capacity (≈13 mAh cm −2 ).