Recently, a joint research team led by Prof. Wang Shuhua, Prof. Sang Yuanhua and Prof. Liu Hong from the State Key Laboratory of Crystal Materials, Shandong University, has made new progress in the regulation of carrier transport on manganese-based cathodes in aqueous zinc batteries. The paper entitled “Manganese Based Proton Reservoir Trigger Proton Diversion Effect for Ultrahigh-Capacity Aqueous Zinc-Ion Batteries” has published online in the international journal Advanced Materials on Mar. 23, 2026.

First author of the paper is PhD student Zhao Xiaoru at the State Key Laboratory of Crystal Materials, Shandong University. Corresponding authors are Prof. Wang Shuhua, Prof. Sang Yuanhua and Prof. Liu Hong at Shandong University, and Prof. Fan Jiadong at ShanghaiTech University. The State Key Laboratory of Crystal Materials, Shandong University, is the leading corresponding institution for this research.

MnO₂ has been extensively used as cathodes in aqueous zinc-ion batteries (ZIBs) due to its high output voltage, and various crystallographic structures. However, Zn²⁺ intercalation in MnO₂ faces multiple obstacles, which mainly stems from electrostatic interaction between Zn²⁺ and skeleton, coverage of by-product Zn₄SO₄ (OH)₆·xH₂O (ZSH) on cathode and H⁺ preferential occupation for active sites. The current literatures have predominantly focused on reducing the interaction between Zn²⁺ and the skeleton and suppressing by-product ZSH on cathode surface. However, in H⁺/Zn²⁺ co-intercalation storage mechanism, the two ionic species exhibit the competition intercalation. The hindrance of H⁺ preferential insertion for Zn²⁺ intercalation kinetics remains critically overlooked, which severely affects Zn²⁺ transport and limits Zn storage. Consequently, achieving fast zinc ion transport kinetics remains a big challenge.

The research team proposed proton diversion strategy to regulate H⁺/Zn²⁺ intercalation in manganese-based cathodes. The designed manganese-based cathode comprises MnOOH, K⁺ doped α-MnO₂ (KMO), and carbon nanotubes (CNTs) (denoted as KMO-MnOOH). The MnOOH can transform into the active material β-MnO₂ via the in-situ release of protons, thereby triggering proton diversion effect.

(1) MnOOH with a 1×1 tunnel structure undergoes in-situ proton release during cycling and transforms into β-MnO₂. β-MnO₂ exhibits strong H⁺ adsorption and unique tunnels for rapid H⁺ migration, leading to preferential H⁺ intercalation. This “proton diversion effect” preserves active sites in KMO and boosts Zn²⁺ storage. (2) The proton diversion effect is accompanied by H⁺ release from MnOOH, which reduces the by-product ZSH on the cathode, maintaining continuous Zn²⁺ transport channels and enabling deep Zn²⁺ intercalation. MnOOH also stabilizes electrolyte pH, synergistically optimizing cathodic proton intercalation and anodic Zn deposition kinetics. (3) Benefiting from the proton reservoir and diversion effect, the KMO-MnOOH cathode delivers an ultrahigh specific capacity of 645.6 mA h g⁻¹at 0.3 A g⁻¹ and excellent cycling stability (239.3 mA h g⁻¹ after 950 cycles at 2 A g⁻¹). This breaks the inherent capacity limitation of conventional Mn-based cathodes (typically 200–500 mA h g⁻¹), offering a promising pathway for ultrahigh-capacity Mn-based cathodes.

This work provides new insights into the regulation of H⁺/Zn²⁺ intercalation and inhibition of by-product formation in Zn//MnO₂ batteries. Notably, this strategy has not yet been reported in the battery field.

This research was supported by the National Natural Science Foundation of China and State Key Laboratory of Crystal Materials. The authors thank the staff from the BL16U1 beamline of Shanghai Synchrotron Radiation Facility (SSRF) for their support.