Three-Dimensional Interface Architectures (Task 1)
Above, lithographically created arrays of silicon micro-nanostructures with controlled spacing in a) two dimensions and b) three dimensions. Lithiating these structures, monitoring the Si expansion with SEM, and analyzing the electrochemical capacity retention with cycling is leading to the development of design rules for 3D Si anodes.
The three-dimensional (3D) Interface Architectures task focuses on the design and electrochemical evaluation of three-dimensional electrode/electrolyte interfaces using novel scaffolds, nano-architectures, and surface structures. Studies conducted in this task area explore both anode/electrolyte and cathode/electrolyte interfaces.
Creative synthetic procedures form the basis for designing electrode/electrolyte materials and architectures and for understanding surface or interfacial processes that occur during electrode synthesis or electrochemical reactions. In this respect, this task focuses on three major materials areas: (1) C-based electrodes, (2) Si-based electrodes, including Si-C composites, and (3) a newly created focus on electrode/electrocatalyst materials for Li-O2 cells, in which a novel approach to designing metal oxide electrodes/electrocatalysts from Li2O-rich metal oxides, such as Li5FeO4 (5Li2O•Fe2O3). Despite the extensive research that has been, and continues to be, conducted worldwide on C and Si-based electrodes, CEES strives to make notable and original contributions to the design of new Si and C architectures that may lead to enhanced electrochemical behavior. At the same time, atomic layer deposition is being used to fabricate new surface compositions and structures that will enhance the electrochemical stability of anode and cathode materials at high and low potentials vs. metallic lithium. Task 1 is well-integrated with the Control of Interfacial Processes task and has a strong Theory component; these cross-cutting tasks have provided a deep understanding of complex structural and electrochemical phenomena associated with the materials under investigation.