The battery, which dates back to the late 18th and early 19th century, has undoubtedly contributed to the development of current technology. The last hundred years have seen an extensive variety of battery chemistries and configurations, spanning from the basic electrochemical cell of Volta with Cu and Zn electrodes, to the modern thin film battery with lithium-oxide cathodes, solid electrolytes, and graphite anodes.
The lithium-ion (Li-ion) battery stands as the principal technological battery platform. This is because Li-ion technology is known to have considerably more favorable properties than that of other battery chemistries. Such properties include high energy density (~250 Wh/kg) and minimal memory effects.
Following an increase in the development of newer, more complex, and hence more power-consuming technologies, the need for safe, lightweight, and long-lasting batteries has never been greater. As a consequence, it is predicted that the next 10 years will see the Li-ion battery market surge by at-least 50 billion dollars (USD). The market for thin film batteries, in particular, is being driven by the strong demand for technologies that are wearable, transportable, and based on the internet of things (IoT).
Thin Film Battery Construction
Thin film batteries are indeed true to their name; the layers of the anode, cathode, and electrolyte measure at 0.001 mm in thickness. They are typically deposited using physical vapor deposition, via thermal evaporation and sputtering.
Lithium based thin film battery schematic
Due to the increasingly high demand of standard performance metrics for battery technology, studies investigating anode, cathode, and electrolyte materials have dominated current research, and hence, our understanding of such materials has speedily progressed. Complex lithium-oxides such as LiCoO2, LiMn2O4, and LiFePO4, for instance, are generally used to form the cathode. Conversely, the anode is usually comprised of carbon-based materials like graphite or Li metal.
The cathode and anode materials are layered structures which intercalate and de-intercalate lithium while preserving their structure. The electrolyte, which is solid in thin film batteries, must be an effective ion-conductor, a good insulator, and should produce a battery that is light-weight, long lasting, and safe. Ultimately, this is determined by the combination of materials used. Although electrolytes are typically made from lithium phosphorus oxynitride (LiPON), research suggests that ceramics such as lithium lanthanum zinc oxide (LLZO) and lithium lanthanum titanium oxide (LLTO) may be more effective materials.
Angstrom Engineering Battery Deposition Systems
Angstrom Engineering offers their Battery Deposition Systems, which allow deposition of a full range of battery materials, including the thermal evaporation of lithium and sputtering of ceramics and lithium-oxides.
This full featured system was custom created for a partner and integrates dedicated lithium thermal evaporation, lithium-oxide multi-source sputtering, and rapid thermal processing into an ultra-high purity argon environment to provide ideal process flexibility, ease of materials handling, and safety.
Angstrom tools can be incorporated with glove-boxes, so substrate and material handling can be achieved under inert atmospheres. Ultimately these systems enable flexibility for a unique range of process requirements, ease of materials handling, and safety.
This information has been sourced, reviewed and adapted from materials provided by Angstrom Engineering.
For more information on this source, please visit Angstrom Engineering.