Electrochemical energy storage is a cost-effective, sustainable method for storing and delivering energy gener- ated from renewable resources. Among electrochemical energy storage devices, the lithium-ion battery (LIB) has dominated due to its high energy and power density. The success of LIBs has generated increased interest in sodium-ion battery (NaB) technology amid concerns of the sustainability and cost of lithium resources. In recent years, numerous studies have shown that sodium-ion solid-state electrolytes (NaSEs) have considerable potential to enable new cell chemistries that can deliver superior electrochemical performance to liquid-electrolyte-based NaBs. However, their commercial implementation is hindered by slow ionic transport at ambient and chemical/ mechanical incompatibility at interfaces. In this review, various NaSEs are first characterized based on individual crystal structures and ionic conduction mechanisms. Subsequently, selected methods of modifying interfaces in sodium solid-state batteries (NaSSBs) are covered, including anode wetting, ionic liquid (IL) addition, and composite polymer electrolytes (CPEs). Finally, examples are provided of how these techniques improve cycle life and rate performance of different cathode materials including sulfur, oxide, hexacyanoferrate, and phosphate-type. A focus on interfacial modification and optimization is crucial for realizing next-generation batteries. Thus, the novel methods reviewed here could pave the way toward a NaSSB capable of with- standing the high current and cycle life demands of future applications.
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A Physics-based Model Assisted by Machine-Learning for Sodium-ion Batteries with both Liquid and Solid Electrolytes
In the absence of experimental data of fully developed hierarchical 3D sodium solid-state batteries, we developed an improved continuum model by relying on Machine Learning-assisted parameter fitting to uncover the intrinsic material properties that can be transferred into different battery models. The electrochemical system simulated has sodium metal P2-type Na2/3[Ni1/3Fe1/12Mn7/12]O2(NNFMO) as the cathode material, paired with two types of electrolytes viz, the organic liquid electrolyte and a solid polymer electrolyte. We implemented a 1D continuum model in COMSOL to suit both liquid and solid electrolytes, then used a Gaussian Process Regressor to fit and evaluate the electrochemical parameters in both battery systems. To enhance the generalizability of our model, the liquid cell and solid cell models share the same OCV input for the cathode materials. The resulting parameters are well aligned with their physical meaning and literature values. The continuum model is then used to understand the effect of increasing the thickness of the cathode and current density by analyzing the cathode utilization, and the overpotentials arising from transport and charge transfer. This 1D model and the parameter set are ready to be used in a 3D battery architecture design.
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- Award ID(s):
- 2134715
- PAR ID:
- 10543217
- Publisher / Repository:
- ECS
- Date Published:
- Journal Name:
- Journal of The Electrochemical Society
- Volume:
- 171
- Issue:
- 6
- ISSN:
- 0013-4651
- Page Range / eLocation ID:
- 060516
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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