Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Battery up Your Sleeve

13.06.2014

Elastic wire-shaped lithium ion batteries with high electrochemical performance

Flexible smartphones, “intelligent” bracelets, glasses with a built-in computer: for these trends to take off, we need suitable power systems. Chinese scientists have now developed a wire-shaped lithium ion battery that contains electrodes consisting of two composite yarns made of carbon nanotubes and lithium titanium oxide or lithium manganese oxide. As the researchers report in the journal Angewandte Chemie, they were able to weave their batteries into light, flexible, elastic, and safe textile batteries with a high energy density.

Previous methods for producing wire-shaped electrochemical supercapacitors by twisting two fiber electrodes together resulted in systems with inferior performance that prevented them from being brought to the market. Lithium ion batteries can attain significantly higher energy density, but have not previously been produced in wire form.

In addition to other barriers, the safety problems associated with lithium ion batteries really come into play. The source of the safety problem is dendritic lithium, which can form during over-charging, “growing” out of the anode and causing a short circuit. This can cause the battery to ignite. This seems especially critical for wire-shaped batteries that can be stretched, twisted, and bent during use.

A team led by Huisheng Peng from Fudan University in Shanghai has now succeeded in producing wire-shaped lithium ion batteries that have a high energy density and are also safe. Their success results from the special structure as well as the materials used. The anode and cathode are two fibers made of parallel multiwalled carbon nanotubes that contain either lithium titanium oxide (LTO) or lithium manganese oxide (LMO) particles, respectively.

When the battery is charging, lithium ions are transferred from the LMO lattice to the electrolyte and then into the LTO lattice of the anode. The reverse process occurs as the battery is being discharged. Because the Li insertion takes place at ~1.5 V (vs. Li/Li+) for the applied LTO composite electrode, the chance of short circuit caused by dendritic lithium would be small and therefore the batteries are safe.

The parallel arrangements of continuous carbon nanotubes hold the nanoparticles; they are also efficient pathways for charge transport and serve as current collectors. The two electrode yarns are arranged in parallel, separated by a layer of insulator, and enclosed in a heat-shrinkable tube.

To make the wires elastic, they can be wrapped around an elastic fiber such as polydimethylsiloxane and coated with a thin-layer gel electrolyte. Neither repeated stretching to twice its original length nor thousands of deformation cycles reduces the battery capacity.

The wire-shaped batteries can be spun into long fibers and woven into a fabric that can be incorporated into textiles.

About the Author

Dr. Huisheng Peng is a Professor of Department of Macromolecular Science and Laboratory of Advanced Materials at Fudan University. His research centers on functional composite materials and their energy applications. Peng and co-workers created aligned carbon nanotube/polymer composites and developed novel wire-shaped solar cells, Li-ion batteries, and supercapacitors.

Author: Huisheng Peng, Fudan University, Shanghai (China), http://www.polymer.fudan.edu.cn/polymer/research/Penghs/member_en.htm

Title: Elastic and Wearable Wire-Shaped Lithium-Ion Battery with High Electrochemical Performance

Angewandte Chemie International Edition, Permalink to the article: http://dx.doi.org/10.1002/anie.201402388

Huisheng Peng | Angewandte Chemie

Further reports about: batteries battery circuit dendritic elastic electrode electrodes electrolyte fiber fibers lattice manganese materials titanium

More articles from Life Sciences:

nachricht NIH Scientists Determine How Environment Contributes to Several Human Diseases
27.11.2014 | National Institute of Environmental Health Sciences (NIEHS)

nachricht Copper on the Brain at Rest
27.11.2014 | Lawrence Berkeley National Laboratory

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Anzeige

Anzeige

Event News

Regional economic cooperation in Central Asia

21.11.2014 | Event News

Educating the Ecucators

13.11.2014 | Event News

36th Annual IATUL Conference 2015: Call for papers and posters

12.11.2014 | Event News

 
Latest News

SLU Researcher Finds an Off Switch for Pain

27.11.2014 | Health and Medicine

University of Minnesota engineers make sound loud enough to bend light on a computer chip

27.11.2014 | Physics and Astronomy

Tropical Depression 21W Forms, Philippines Under Warnings

27.11.2014 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>