Zinc-based batteries offer a safe, inexpensive alternative to fire-prone lithium-based batteries, yet have been historically limited by poor rechargeability. The Naval Research Laboratory (NRL) has eradicated this centuries-old roadblock by developing a 3D zinc (Zn) “sponge” electrode architecture comprising interpenetrating networks of Zn scaffolding and void space. The design characteristics of NRL’s 3D Zn sponge yield superior electrochemical properties when cycled in alkaline electrolytes compared to conventional Zn powder-composite electrodes. The longstanding problem of dendrite formation upon cycling is solved by distributing current more homogeneously in 3D throughout the electrode volume, while the void structure constrains dissolution/precipitation processes within the electrode. This breakthrough transforms the future capabilities and performance of the entire family of Zn-based alkaline batteries. By swapping in NRL’s 3D Zn sponge for traditional powdered or foil Zn anodes, NRL has demonstrated fully rechargeable nickel–zinc prototype cells that challenge Li-ion performance, but which use aqueous-based cell chemistry that is inherently safer than the nonaqueous liquids used in Li batteries, thereby meeting the goal of a robust, energy dense, and safe battery.

Application Areas

  • High charge-storage capacity (>90% of theoretical Zn specific capacity on single-discharge)
  • Supports high-power operation, including under complex duty-cycle loads
  • Dendrite-free operation through extended charge–discharge cycling at deep levels of Zn utilization
  • Fused monolithic electrode structure that can be molded to desired form factor
  • Applicable to multiple aqueous-alkaline battery chemistries, including Zn–air, Ni–Zn, Ag–Zn, and MnO2–Zn

Application Areas

  • Primary (disposable) batteries
  • Secondary (rechargeable) batteries
  • 3D solid-state batteries


  • “Wiring Zinc in Three Dimensions Re-Writes Battery Performance—Dendrite-Free Cycling,” Energy Environ. Sci., 7 (2014) 1117–1124.
  • “Retaining the 3D Framework of Zinc Sponge Anodes upon Deep Discharge in Zn–Air Cells,” ACS Appl. Mater. Interfaces, 6 (2014) 19471–19476.
  • “Minimizing Shape Change at Zn Sponge Anodes in Rechargeable Ni–Zn Cells: Impact of Electrolyte Formulation.” J. Electrochem. Soc., 163 (2016) A351–A355.

Licensing and Collaboration Opportunities
US Patent Nos. 7,255,924; 7,672,114; 7,724,500; 8,475,698; 9,017,780; 9,058,931; 9,093,721; 9,105,402 and US Patent Publication Nos. US20130177756; US20140147757; and US20150118552 are available for license to companies with commercial interest. Collaborative research and development is available under a Cooperative Research and Development Agreement (CRADA).

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