Ener1 Inc’s battery division Enerdel believes that they can reduce the cost of lithium ion batteries to half of their current cost when produced in high volume. This will mean a payback of two years instead of eight years for making a car a hybrid and having the fuel savings pay for the extra costs.
EnerDel believes longevity, safety and cost are the most important elements demanded by the automotive customers. To achieve these key attributes, EnerDel is convinced that a non-graphite anode material is key for success in automobile battery business. EnerDel has developed our own Lithium Titanate Anode material in collaboration with Argonne National Laboratory (ANL) for HEV applications. We have also developed a Hard Carbon anode lithium ion battery for PHEV/EV applications.
Mechanical Design Advantages
The mechanical design inside the EnerDel cell is a stack design where the electrodes are stacked on top of each other, i.e. multiple anode and cathode pairs of electrodes are stacked on top of each other. This differs markedly from almost all lithium ion batteries in the market today, including batteries for notebook computers, mobile phones, power tools, etc., which are using a wound design, i.e. where one anode and one cathode electrode of the same lengths are wound up.
Manufacturing Process Advantage
EnerDel’s stack design in the cell is accomplished with a fully automated mass production process.
In separate work, the latest development in biology-based circuity comes courtesy of researchers at MIT who have crafted a battery with an anode wired-up using a virus. These nanoscale batteries can be printed onto most conducting surfaces.
The virus’ coat of proteins self-assembles from thousands of identical proteins, which allows researchers to manipulate the protein structure in order to allow the virus to serve as a template for other materials. In this case, a few tweaks to the protein’s sequence allowed it to interact with cobalt oxides, which can function as anodes in lithium-based batteries.
But an anode is only part of a functional battery. The new paper describes a process that allows the battery components to largely self-assemble. The researchers built a template of polydimethylsiloxane that contained round posts roughly five microns in diameter. On top of the post, they deposited a dozen alternating layers of two solid electrolytes: polyethlenimine and polyacrylic acid. These layers formed a cap on the substrate about 150nm thick. On top of that, the researchers deposited the M13 virus, dipped in a cobalt oxide solution that converted the viral layer into the nanobattery’s anode.
Less than a centimeter’s worth of the batteries managed to hold anywhere from 375 to 460 nAh, depending on the charging conditions.
These batteries aren’t likely to be solutions for big problems, like laptop batteries, but they could find a niche in the world of miniaturized, low-power devices.
Stamped microbattery electrodes based on self-assembled M13 viruses
The fabrication and spatial positioning of electrodes are becoming central issues in battery technology because of emerging needs for small scale power sources, including those embedded in flexible substrates and textiles. More generally, novel electrode positioning methods could enable the use of nanostructured electrodes and multidimensional architectures in new battery designs having improved electrochemical performance. Here, we demonstrate the synergistic use of biological and nonbiological assembly methods for fabricating and positioning small battery components that may enable high performance microbatteries with complex architectures. A self-assembled layer of virus-templated cobalt oxide nanowires serving as the active anode material in the battery anode was formed on top of microscale islands of polyelectrolyte multilayers serving as the battery electrolyte, and this assembly was stamped onto platinum microband current collectors. The resulting electrode arrays exhibit full electrochemical functionality. This versatile approach for fabricating and positioning electrodes may provide greater flexibility for implementing advanced battery designs such as those with interdigitated microelectrodes or 3D architectures.