Synergistic Regulation of Anode and Cathode Interphases via an Alum Electrolyte Additive for High‐Performance Aqueous Zinc‐Vanadium Batteries
Lingjun He, Chuyuan Lin, Lingxing Zeng, Fuyu Xiao, Hui Lin, Peixun Xiong, Qingrong Qian, Qinghua Chen, Zhenhua Yan, Jun Chen
Abstract
Abstract A zinc (Zn) metal anode paired with a vanadium oxide (VO x ) cathode is a promising system for aqueous Zn–ion batteries (AZIBs); however, side reactions proliferating on the Zn anode surface and the infinite dissolution of the VO x cathode destabilise the battery system. Here, we introduce a multi‐functional additive into the ZnSO 4 (ZS) electrolyte, KAl(SO 4 ) 2 (KASO), to synchronise the in situ construction of the protective layer on the surface of the Zn anode and the VO x cathode. Theoretical calculations and synchrotron radiation have verified that the high‐valence Al 3+ plays dual roles of competing with Zn 2+ for solvation and forming a Zn−Al alloy layer with a homogeneous electric field on the anode surface to mitigate the side reactions and dendrite generation. The Al‐containing cathode–electrolyte interface (CEI) considerably alleviates the irreversible dissolution of the VO x cathode and the accumulation of byproducts. Consequently, the Zn||Zn cell with KASO exhibits an ultra‐long cycle of 6000 h at 2 mA cm −2 . Importantly, the VO x cathodes (VO 2 , V 2 O 5 and NH 4 V 4 O 10 ) in the ZS−KASO electrolyte showed excellent cycling stability, including Zn powder||VO 2 cells and Zn||VO 2 pouch cells. Even better, the full cell exhibits excellent cycling stability at low negative/positive (N/P) ratio of 2.83 and high mass loading (~16 mg cm −2 ). This study offers a straightforward and practical reference for concurrently addressing challenges at the anode and cathode of AZIBs.