Researchers at the CSIR-National Chemical Laboratory (CSIR-NCL), Pune, have developed an intrinsic self-healing hydrogel polymer electrolyte for rechargeable Zinc-metal Batteries (RZMBs), addressing major safety and durability challenges associated with dendrite growth and mechanical damage. This research has been published in the prestigious journal Advanced Energy Materials.

The work was carried out by a research team led by Dr Sreekumar Kurungot, Chief Scientist, Physical and Materials Chemistry Division, and Ms Priyanka Pandinhare Puthiyaveetil, PhD researcher. The hydrogel polymer electrolyte, named PHBC-4, has been engineered with a combination of hydrogen bonding, dynamic polar covalent B–O interactions, and Zn–O coordination bonding to provide a robust and dynamic polymer network. This innovative structural design significantly suppresses dendrite formation, a critical factor responsible for short-circuiting and battery failure in traditional zinc-metal batteries.

A key highlight of the material is its autonomous self-healing capability, where the hydrogel can restore up to 93% of its mechanical strength within just five minutes. The researchers demonstrated this feature by powering an LED using a flexible pouch cell constructed with the PHBC-4 electrolyte. Even after cutting the pouch cell with scissors, the internal network reassembled itself, and the LED continued to glow, confirming its potential for flexible and wearable electronic devices.

Rechargeable zinc-metal batteries are gaining prominence due to their high safety, abundant raw materials, and environmental compatibility. However, issues such as dendrite growth, hydrogen evolution reactions, and mechanical failure have limited their use in real-world applications. The PHBC-4 electrolyte overcomes these barriers by enabling smooth and uniform zinc deposition and by maintaining structural integrity even under mechanical stress.

The study reported that the PHBC-4 system delivered high ionic conductivity (4.6 × 10?² S cm?¹), a cation transference number of 0.89, and exceptional cycling stability of over 490 cycles when paired with a Zn-doped MnO? cathode. In Zn||Zn symmetric cells, the electrolyte ensured stable plating–stripping behaviour for more than 1032 hours, demonstrating its high durability.

This breakthrough represents an important advancement toward the development of next-generation sustainable batteries suitable for flexible, wearable, and deformable electronic applications.

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Reference: Self-Healing Hydrogel Electrolyte Enabled by Dynamic Polar Covalent and Noncovalent Interactions for High-Performance Rechargeable Zinc-Metal Batteries: A Leap toward Sustainable Energy Storage, Sreekumar Kurungot et al. Adv. Energy Mater. 2025, DOI: 10.1002/aenm.202502883