Zinc-ion batteries
(ZIBs) is a promising electrical
energy storage candidate due to its
eco-friendliness, low cost, and intrinsic
safety, but on the cathode the
element dissolution and the formation
of irreversible products, and on
the anode the growth of dendrite as
well as irreversible products hinder
its practical application. Herein, we
propose a new type of the inorganic
highly concentrated colloidal electrolytes
(HCCE) for ZIBs promoting
simultaneous robust protection of both cathode/anode leading to an effective suppression of element dissolution, dendrite, and irreversible products
growth. The new HCCE has high Zn2+
ion transference number (0.64) endowed by the limitation of SO4
2−, the competitive ion conductivity (1.1 × 10–2
S cm−
1) and Zn2+
ion diffusion enabled by the uniform pore distribution (3.6 nm) and the limited free water. The Zn/HCCE/α-MnO2 cells exhibit
high durability under both high and low current densities, which is almost 100% capacity retention at 200 mA g−1 after 400 cycles (290 mAh g−
1)
and 89% capacity retention under 500 mA g−1 after 1000 cycles (212 mAh g−1). Considering material sustainability and batteries’ high performances,
the colloidal electrolyte may provide a feasible substitute beyond the liquid and all-solid-state electrolyte of ZIBs.