Performance Modeling and Design of Ultra-High Power Microbatteries

Abstract

High power density microbatteries could enable new capabilities for miniature sensors, radios, and industrial electronics. There is, however, a lack of understanding on how battery architecture and materials limit power performance when battery discharge rates exceed 100 C. This paper describes the development and application of an electrochemical model to predict the performance of microbatteries having interdigitated bicontinuous microporous electrodes, discharged at up to 600 C rates. We compare predicted battery behavior with measurements, and use the model to explore the underlying physics. The model shows that diffusion through the solid electrodes governs microbattery power performance. We develop design rules that could guide the development of improved batteries. High power density microbatteries would enable new capabilities for miniature sensors, radios, and industrial electronics.1-4 Recent improvements in electrode architectures, materials, and fabrication technologies have enabled microbatteries with power densities as high as 7.4 mW cm −2 μm −1 , which is about 100 times greater than power densities provided by larger conventional format batteries.5-9 The ultrahigh power densities were achieved by the simultaneous reduction of ion and electron transport resistances across the anode, cathode, and electrolyte. Fabricating electrodes with increasingly fine nanostructures that provide shorter ion and electron transport paths has been the main strategy for reducing transport resistances.2,5-7,10-18 However, as the electrode dimensions decrease, electrode fabrication and incorporating large volume fractions of high capacity materials into the nano architectures (important for obtaining high energy densities) become more difficult. Additionally, the larger surface area leads to increased SEI formation during battery fabrication. To realize both high power and high energy density, it is important to understand how battery architecture and materials affect the physical processes that limit power density and improve energy density, and to develop experimentally validated design rules that address the many engineering constraints in full battery assemblies.Simulations of battery operation, considering ion transport across both the anode and cathode regions, can be used to assist in battery design and optimization. A key parameter in understanding battery discharge is the C rate, where the time it takes to discharge a battery in one hour is 1 C rate. An X C rate discharge corresponds to a current density X times the 1 C rate current density. The validity of battery discharge models has rarely been explored above discharge rates of 25 C, [19][20][21][22][23][24][25][26][27][28][29][30][31][32] with only a few exceptions. 33-37 To our knowledge, there is no published work that validates models for batteries discharged at the 100-1000 C rates relevant to high power microbatteries. There is thus a need for an experimentally validated battery model that describes the physical processes that limit battery performan...

First ptychographic X-ray computed tomography experiment on the NanoMAX beamline

“…It was required to have an internal 3D structure which is not too complicated so that the reconstructed volume could be easily compared with the expected structure. We decided to use an artificial nickel-based inverse opal material (Pikul et al, 2017(Pikul et al, , 2019 as it offers a simple repeating internal 3D structure in all directions, whose period size can be chosen during sample synthesis, and a strong contrast between nickel and air.…”

Low‐Energy Room‐Temperature Healing of Cellular Metals

“…Applying a negative potential (−1.8 V) to the fractured cellular nickel, relative to a nickel counter electrode, healed the sample by driving electrons through the conductive nickel to the fracture location and reducing nickel ions in the electrolyte to solid nickel. The open‐cell pores enabled rapid ion transport to the fracture site, as previously demonstrated in battery electrodes . Nickel electrodeposited on both sides of the fractured strut grew until the growth fronts merged, forming a continuous strut (Figure d).…”

3D-Microbattery Architectural Design Optimization Using Automatic Geometry Generator and Transmission-Line Model

“…We finalize this section by summarizing the advantages of our optimization system over the previously proposed 3D battery optimization methods based on the continuum model, where only simple structural change of the interdigitated electrodes is considered ( Zadin et al., 2010 , 2011 ; Zadin and Brandell, 2011 ; Priimägi et al., 2016 ; Miranda et al., 2016 ; Pikul et al., 2017 ). First, the use of the low-cost transmission line model allows evaluations of a variety of 3D battery geometries (e.g., 200,000 geometries), which is difficult with the continuum model.…”

“…So far, battery optimizations have been carried out using continuum simulations ( McKelvey et al., 2020 ). However, most of such methods investigate only the influence of simple structural change (such as width, length, pitch, and end shape) of the interdigitated electrodes to the battery performance ( Hart et al., 2003 ; McKelvey et al., 2017 ; Zadin et al., 2010 , 2011 ; Zadin and Brandell, 2011 ; Priimägi et al., 2016 ; Miranda et al., 2016 ; Pikul et al., 2017 ; Li et al., 2018 ). Although Zadin et al.…”