Zinc-ion hybrid capacitors (ZIHCs) are gaining much attention for their high energy density; however, the charge storage in traditional ZnSO₄ electrolyte is limited by its low ionic conductivity, resulting in low specific capacity, rate capability, and gravimetric energy/power density at high rates. Herein, we report a ZIHC with high charge storage, enhanced rate capability, and superior energy/power density by introducing Na₂SO₄ in the traditional ZnSO₄ electrolyte. The addition of Na₂SO₄ contributes immensely to the enhancement of capacitive charge storage in the activated carbon cloth positive electrode at high rates and shields the zinc anode from dendrite formation, resulting in excellent electrochemical performance. Specifically, the ZIHC with ZnSO₄/Na₂SO₄ electrolyte presents high electrical and ionic conductivity, high specific capacity (152 mAh g⁻¹), improved rate capability, and gravimetric energy density (20 Wh kg⁻¹ at 1692 W kg⁻¹). In contrast, the ZIHC with traditional ZnSO₄ electrolyte delivers a much lower energy density at high rate (4.5 Wh kg⁻¹ at 50 mA cm⁻²). In-situ Raman, nuclear magnetic resonance, and ex-situ X-ray diffraction demonstrate the inclusion of proton adsorption/desorption in the charge storage process. The proton storage process plays a vital role in the formation/dissolution of Zn(OH)₂ analogs, extension of the voltage window to 1.9 V without compromising the Coulombic efficiency and overall charge storage. This article highlights the importance of electrolyte modification for enhancing the electrochemical performances of ZIHCs.

锌离子混合电容器（ZIHC）因其高能量密度而备受关注。然而，传统的ZnSO ₄电解质中的电荷存储受到其低离子电导率的限制，从而导致低比容量，速率能力以及高速率下的重量能量/功率密度。在本文中，我们报道了通过在传统的ZnSO ₄电解质中引入Na ₂ SO ₄，具有高电荷存储，增强的倍率能力和优异的能量/功率密度的ZIHC 。Na ₂ SO _4的添加有助于高速率地增强活性炭布正极中的电容电荷存储，并保护锌阳极免受枝晶形成，从而实现出色的电化学性能。具体而言，与ZIHC的ZnSO ₄ /钠₂ SO _4所电解质呈现高的电和离子传导性，高比容量（152毫安克^-1），改进的速率能力，并且重量能量密度（20瓦千克^-1在1692公斤w ^ ^{- 1}）。相比之下，具有传统ZnSO ₄电解质的ZIHC可以在高速率下提供低得多的能量密度（50 mA cm ^-2时为4.5 Wh kg ^-1）。原位拉曼，核磁共振和异位X射线衍射证明在电荷存储过程中包括质子吸附/解吸。质子存储过程在Zn（OH）₂类似物的形成/溶解，电压范围扩展到1.9 V而不损害库仑效率和总体电荷存储方面起着至关重要的作用。本文强调了电解质改性对增强ZIHCs电化学性能的重要性。