Batteries with more muscle

By peering deep into our muscles, a team of scientists in China and the United States is finding inspiration for building better batteries. The results may eventually power mobile phones, laptops and other consumer electronic devices. “Nature is marvelous and amazing, and learning from it is very interesting,” says Maowen Xu from the research team, reflecting on the path from looking at muscles to building battery electrodes.

Xu and his collaborators, based at Southwest University in Chongqing, China and the Massachusetts Institute of Technology in the United States, published their work in Energy Storage Materials. They are taking lessons from nature to help them tackle significant challenges in the emerging field of lithium-tellurium battery technology.

One of their motivations for learning from the natural world is to protect it from the effects of human activities. Xu points out that ever-increasing pressures on the environment are driving worldwide efforts to develop low-cost, efficient and sustainable energy storage systems. Rechargeable batteries are among the most useful options, but existing systems based on lithium-ion technology suffer from significant limitations. The amount of energy they can store in a given volume is far from optimal, and other technical problems include low conductivity. “These traditional batteries are just no longer ideal for satisfying the demand of small electronic devices,” says Xu.

Muscles need a rich supply of blood to deliver the oxygen and nutrients that meet their high energy demands. This is achieved via an extensive network of fine blood capillaries, ensuring every cell has a capillary nearby (see image). This natural efficiency is the inspiration for the “muscle structured” battery electrode created by Xu and his colleagues. Tiny carbon spheres loaded with tellurium take the place of the muscle cells. Electricity-conducting carbon nanotubes are arranged like the blood capillaries. The nanotubes transport electrons and ions — the essential “blood” of electrical circuits — while the carbon-tellurium "cells" offer a tightly packed structure for storing electrical energy.

When assessing all of their complex technical data, the researchers summarize the overall performance of their innovative electrode assembly as “excellent”. It achieves a high energy storage capacity that can be sustained through 500 cycles of charge and discharge.

Work at the research laboratory level must be scaled up and further developed before this technology can be put to use in the real world of everyday applications. That is the next challenge for the research team, and it will require collaboration with and input from commercial partners. The researchers also emphasize that their current achievements point to “further new ideas for developing exceptional electrodes for energy storage applications.” The story of biologically inspired battery systems may have more chapters to come.

This article is based on content from: Xu, M. et al.: "Muscle-like electrode design for Li-Te batteries," Energy Storage Materials (2017)