Researchers at Hong Kong Polytechnic University (PolyU) developed a highly flexible and high-energy textile lithium battery that provides a more stable, longer-lasting and safer power supply for wearable electronics with a wide variety of uses, such as medicine, 'smart' textiles, Smartphones, GPS and IoT.
Professor Zheng Zijian leads the research team of the "Institute of Textiles and Clothing" at PolyU in the development of a highly flexible, high-energy textile lithium battery. Image: PolyU
The novel, lightweight textile lithium battery from PolyU has a high energy density of more than 450 Wh / L and excellent flexibility - with a bending radius of less than 1 mm and a foldability of over 1.000 cycles with little decrease in capacity.
In comparison, current flexible lithium batteries can only achieve a bending radius of about 25 mm and a significantly lower power of less than 200 Wh / L.
The textile lithium battery, which is less than 0,5 mm thick, has a fast charge / discharge capability and long life compared to conventional lithium batteries.
The innovation developed by the research team of the “PolyU Institute of Textiles and Clothing” (ITC) won three prizes at the last “International Inventors' Fair” in Geneva.
Professor Zheng Zijian, who leads the ITC research team, said, “Wearable technology has been identified as the next global big market opportunity after smartphones. Global portable device market sales are projected to skyrocket annually by over 20 percent and reach $ 2024 billion by 100. "
“As all portable electronics require a portable power supply, our novel technology in the manufacture of textile lithium batteries offers a promising solution for a variety of next generation applications ranging from healthcare, infotainment, sports, aerospace, fashion, IoT up to the applications that can even surpass our current expectations ”.
Lithium batteries are currently the dominant rechargeable battery on the market due to their relatively high energy density and long service life. Since conventional bulky heavy lithium batteries are not readily usable in portable devices, scientists over the past decade have endeavored to develop flexible lithium batteries - often using metal foils as current collectors.
However, the shortfalls in energy density, flexibility, mechanical ruggedness, and cycle life can only be remedied by the development of PolyU's textile lithium battery.
PolyU's patented novel Polymer-Assisted Metal Deposition (PAMD) technology applies highly conductive metals, such as copper (Cu) and nickel (Ni), evenly and conformally to pre-treated textile fabrics. Such fabricated metal fabrics with low sheet resistance and high surface area serve as current collectors in the battery.
After adding active materials as the cathode and anode, the metal meshes are integrated with the separator and the electrolyte in a textile lithium battery.
The laboratory tests carried out by the ITC team showed that the textile lithium battery has extremely high mechanical stability, durability and safety under deformation.
When the battery is repeatedly half-folded, rotated at different angles, or wrinkled freely, its voltage window remains unchanged. About 1000 bending tests showed that the battery can be bent with low capacity decrease.
Safety tests involving continuous hammering, cutting with scissors, and puncturing with a nail showed that the battery can provide stable output for electronic components without the risk of fire or bursting. The research report appeared in "Nature Communications".
The Hong Kong Polytechnic University
