Recently, a research paper collaborated on by Zhejiang VASTECH Technology Co., Ltd. (hereinafter referred to as "Hanwei Technology"), University College London (UCL) and the team from South China University of Technology has been officially published in the journal Nature Communications. As a core collaborating institution, Hanwei Technology has deeply participated in the fabrication process of self-assembled zinc anodes, and developed a 17.36 Ah large-format zinc soft-pack battery. This has greatly improved the cycling stability of large-sized soft-pack batteries and will accelerate the industrial development of zinc-ion batteries.

About Nature Communications
Nature Communications is a sub-journal under the UK Nature Portfolio. It is an online-only multidisciplinary journal, a comprehensive periodical dedicated to publishing high-quality research papers across various fields including biology, physics and chemistry. Papers published in this journal represent significant advances that are of great importance to experts in each respective field.

01
Research Background
Aqueous zinc-ion batteries offer a sustainable alternative to lithium-ion batteries owing to abundant zinc reserves, high safety and favourable environmental friendliness. Nevertheless, issues such as hydrogen evolution in electrolytes and the disordered diffusion of H⁺, Zn²⁺ and SO₄²⁻ can trigger zinc dendrite formation, side reactions and reduced Coulombic efficiency during zinc nucleation.

Against this backdrop, this study constructed ion separation acceleration channels via layer-by-layer self-assembly of flocculant poly(allylamine hydrochloride) and its tautomer poly(acrylic acid), to simultaneously modulate the diffusion of cations and anions in electrolytes. The dual-ion channels formed by strong electrostatic interactions between carboxylate anions and ammonium cations can block SO₄²⁻ and facilitate uniform zinc deposition along the Zn(002) plane. The Cu||Zn cell maintained a Coulombic efficiency of 99.8% after 1600 cycles. Using a facile layer-by-layer self-assembly fabrication process for zinc anodes, the Ah-level pouch cell (17.36 Ah) achieved a high loading mass (>8 mg cm⁻²), demonstrating practical feasibility for large-scale applications, and retained 93.6% of its capacity after 250 cycles at 1.7 C (35.3 min). This research realized more uniform zinc deposition and improved the cycling stability of large-format pouch cells, opening new possibilities for the commercial development of zinc-ion batteries.

02
Technical Highlights
The research team fabricated layer-by-layer self-assembled PAH/PAA multilayer films using poly(allylamine hydrochloride) (PAH) and its tautomer poly(acrylic acid) (PAA). This approach not only markedly enhanced electrochemical performance but also improved the environmental sustainability of the technology, making it a viable candidate for large-scale deployment and presenting multiple technical highlights.

Improved electrode reversibility and stability
Layer-by-layer self-assembled poly(acrylic acid)/polyethylenimine multilayer films with high mechanical strength and ionic conductivity can effectively enhance the reversibility and stability of zinc anodes.

Modulated ion transport
The ion separation acceleration channels built by the multilayer films endow the material with high affinity for zinc to regulate the Zn²⁺ desolvation process, and can trap SO₄²⁻ ions to suppress by-product formation.

Dendrite growth suppression
In addition, the poly(acrylic acid)/polyethylenimine layers can induce zinc deposition along the (002) crystal plane to form uniform and dense layers and inhibit dendrite generation.

Long-cycle stability and high Coulombic efficiency
Since poly(acrylic acid)/polyethylenimine multilayer films can boost interfacial Zn²⁺ transport kinetics and thermal stability, the Zn||Zn symmetric cell achieved long-term stability exceeding 1100 h at 1 mA cm⁻² and 1 mAh cm⁻². Meanwhile, the Cu||Zn asymmetric cell delivered a Coulombic efficiency of 99.8% and a high capacity of 396 mAh cm⁻² after 1600 cycles at 0.5 mA cm⁻² and 0.25 mAh cm⁻².

High discharge capacity
The polyethylenimine/poly(acrylic acid) multilayer films enabled the Zn||VO₂ pouch cell to retain a high discharge capacity of 17.36 Ah after 250 cycles at 1.7 C under high loading conditions.

The researchers anticipate that this work can inspire a strategy of constructing ion separation acceleration channels through polyelectrolyte layer-by-layer self-assembly to protect metal anodes, thereby advancing the practical application of aqueous rechargeable batteries.

Below are schematic diagrams of key experimental results from this paper:

VASTECH's Contributions
In this research, the team focused on overcoming technical challenges of zinc-ion batteries and strived to advance their industrialization through technological innovation.

Performance Improvement
By optimizing battery electrode materials and structural design, Hanwei Technology has significantly boosted the energy density and cycling stability of batteries. While enhancing the charge-discharge efficiency of batteries, it also extends their service life, making them more reliable under high-load applications.

Social Value
Hanwei Technology's innovative achievements in the aqueous battery field have not only broken through technical bottlenecks including electrode material stability and battery cycle life, but also provided important theoretical foundations and practical approaches for the system construction and application of aqueous electrochemical energy storage technology. It deepens research in this field and accelerates its industrialization.

Application Value
The successful development of 17.36 Ah-level pouch cells marks a major breakthrough for Hanwei Technology in aqueous energy storage. At present, this technological achievement is being rapidly deployed in multiple application scenarios such as rail transit, industrial and commercial energy storage, and confined-space energy storage. It improves market acceptance and application scope of aqueous energy storage solutions, and promotes the effective transformation and large-scale application of key technologies.

Up to now, Hanwei Technology’s related products have supported hundreds of technology enterprises, universities and research institutes. Nearly 200 high-impact journal papers covering various fields have been published, with relevant research results successively released in top international journals including Nature and Advanced Materials.