RESEARCH

"Research is creating new knowledge" - Neil Armstrong

TOPICS OF INTEREST 

  • Hybrid Solid-Plastic/Solid Polymer Electrolyte
  • SiNA (Silicon Nano Alloy) Nanocomposite Anode Engineering
  • Flexible, Wearable & Textile High Energy Storage Material & Device Design
  • Multifunctional Nanostructured Material Design and Synthesis for Energy Storage Application
  • Nanoporous/Nanodense Functional Layer Using Plasma Enhanced ALD

Highly Ionically Conductive Solid Electrolyte Membrane
 The development of solid polymer electrolyte membranes for LIB is one of the hottest topics in the battery field. A solid polymer battery will be able to open the door to not only electric vehicle and IT electronics but also a myriad of new applications like energy storage textiles, novel medical devices, and new energy harvesting gadgets. However, the low ionic conductivity hurdle must first be overcome before solid polymer battery can become a reality. The average ionic conductivity of a polymer electrolyte membrane is 10-4 S cm-1, which is several orders of magnitude below the conventional liquid electrolyte’s 10-2~ 10-3 S cm-1. Our polymer electrolyte membrane achieves high ionic conductivities of 10-3 S cm-1 at RT while maintaining mechanical and thermal integrity. We believe that our advances will make all-solid-state batteries a tangible possibility.

Lithium Metal Protection by Plasma-Thermal Dual ALD
 With its high theoretical capacity of 3860 mAh/g, Lithium (Li) metal is the ideal anode material for all sorts of Li batteries such as Li-ion, Li-S, and Li-air. However, practical use of Li anode is limited due to its thermal, chemical, and air stability that leads to poor performance of the battery. Artificial surface protection on Li has proven to be useful to fight the issues without compromising the battery performance when the layer is sufficiently thin. Atomic Layer Deposition (ALD) is one of the most effective way to deposit a very thin, but uniform and conformal coating. Deposition using thermal or plasma ALD can provide limited protection of the lithium metal. However, the combined dual plasma-thermal ALD can yield in a very dense and stable nanoscale surface protection layer which enables prolonged lithium stability in air atmosphere. This approach allows for solid-state electrolyte deposition directly on the lithium metal to attain the much desired all solid state battery.
  
Heterostructured Lithium Deficient Cathode Materials for Li-ion Batteries
The cathode in a Li-ion battery houses all of the Li ions, therefore it is the primary source of the battery's energy. This means that in order to improve battery life and battery power we must improve the cathode. The key to cathode material is its structure. There are several different structures currently used by the battery world, with the layered structure being most popular due to its high energy density. However, the issue with the layered structure is that it must retain some of its lithium ions in order to maintain its stability. This reduces the energy density. Our solution to this problem is introducing pillars to these layers. Therefore, we are currently investigating a multiphase structure (MPS) which is stable enough to be used at high voltages while still having a sufficient energy density. ​​​
Prelithiated Si-Metal Alloy for High Energy Li-Ion Batteries
Silicon anodes are a promising catch on the hunt for high-energy lithium-ion batteries. Even though graphite is the conventional and widely used anode material, silicon (Si) has attracted great attention because of its natural abundance, non-toxicity, and very high theoretical specific capacity of nearly 4200 mAh/g (about ten times more capacity than graphite). However, Si suffers from tremendous volume changes (over 300%) during charge/discharge cycles, and results in pulverization and huge capacity fading over time. This leads to poor battery performance which prevents Si from being implemented in commercial applications. We are currently investigating a prelithiated Si-Metal based alloy as a solution to this problem. Si with metal based alloys can provide a super-elastic flexible metal matrix which would mechanically protect the Si while maintaining electrical integrity, and prelithiation enhances the properties of Si/alloy for long battery life.