Structural batteries from University of Michigan are made of zinc to increase the energy density of the battery and optimize material usage.


  • Increased efficiency
  • Non‑toxic
  • Multifunctional


  • Manufacturing
  • Transportation
  • Small robotics

UN Sustainable Development Goals Addressed

  • Goal 11: Sustainable Cities & Communities

The Challenge

Robots are currently designed to carry single lithium ion batteries that can take up about 20% of the carrying capacity and overall weight. This limits the amount of work a robot can perform, reducing its productivity.

Innovation Details

The batteries function as both an energy source and a structural material that protects the robots. This mimics the multifunctionality of mammalian fat tissues to store energy and protect the internal organs. The battery is non-toxic, zinc-based, and can be conformed to a variety of shapes to protect other parts of the robot. These body-integrated batteries could achieve 72 times as much capacity than the typical single lithium-ion battery. The battery works by passing hydroxide ions between a zinc electrode and the air side through an electrolyte membrane. That membrane is partly a network of aramid nanofibers — the carbon-based fibers found in Kevlar vests — and a new water-based polymer gel. The gel helps shuttle the hydroxide ions between the electrodes. The battery is made from cheap, abundant and largely nontoxic materials, making it more environmentally friendly than traditional batteries. The gel and aramid nanofibers will not catch fire if the battery is damaged, unlike the flammable electrolyte in lithium ion batteries.

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Biomimicry Story

Mammals utilize a layer of fat to both provide insulation for internal organs and store energy for later use.