Polymer hetero-electrolyte enabled solid-state 2.4-V Zn/Li hybrid batteries.

The high redox potential of Zn ^0/2+ leads to low voltage of Zn batteries and therefore low energy density, plaguing deployment of Zn batteries in many energy-demanding applications. Though employing high-voltage cathode like spinel LiNi _0.5 Mn _1.5 O ₄ can increase the voltages of Zn batteries, Zn ²⁺ ions will be immobilized in LiNi _0.5 Mn _1.5 O ₄ once intercalated, resulting in irreversibility. Here, we design a polymer hetero-electrolyte consisting of an anode layer with Zn ²⁺ ions as charge carriers and a cathode layer that blocks the Zn ²⁺ ion shuttle, which allows separated Zn and Li reversibility. As such, the Zn‖LNMO cell exhibits up to 2.4 V discharge voltage and 450 stable cycles with high reversible capacity, which are also attained in a scale-up pouch cell. The pouch cell shows a low self-discharge after resting for 28 days. The designed electrolyte paves the way to develop high-voltage Zn batteries based on reversible lithiated cathodes.
(© 2024. The Author(s).)