skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


Title: Fundamentals and perspectives of electrolyte additives for non-aqueous Na-ion batteries
Despite extensive research efforts to develop non-aqueous sodium-ion batteries (SIBs) as alternatives to lithium-based energy storage battery systems, their performance is still hindered by electrode-electrolyte side reactions. As a feasible strategy, the engineering of electrolyte additives has been regarded as one of the effective ways to address these critical problems. In this review, we provide a comprehensive overview of recent progress in electrolyte additives for non-aqueous SIBs. We classify the additives based on their effects on specific electrode materials and discuss the functions and mechanisms of each additive category. Finally, we propose future directions for electrolyte additive research, including studies on additives for improving cell performance under extreme conditions, optimizing electrolyte additive combinations, understanding the effect of additives on cathode-anode interactions, and understanding the characteristics of electrolyte additives.  more » « less
Award ID(s):
2301719
PAR ID:
10511562
Author(s) / Creator(s):
; ; ; ;
Publisher / Repository:
OAE Publishing
Date Published:
Journal Name:
Energy Materials
ISSN:
2770-5900
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; (, Angewandte Chemie International Edition)
    Abstract The narrow electrochemical stability window of water poses a challenge to the development of aqueous electrolytes. In contrast to non‐aqueous electrolytes, the products of water electrolysis do not contribute to the formation of a passivation layer on electrodes. As a result, aqueous electrolytes require the reactions of additional components, such as additives and co‐solvents, to facilitate the formation of the desired solid electrolyte interphase (SEI) on the anode and cathode electrolyte interphase (CEI) on the cathode. This review highlights the fundamental principles and recent advancements in generating electrolyte interphases in aqueous batteries. 
    more » « less
  2. ; ; (, ACS Catalysis)
    CO2 electroreduction (CO2ER) by using renewable energy resources is a promising method to mitigate the CO2 level in the atmosphere as well as producing valuable chemicals. Local environment at the electrode-electrolyte interface plays a key role in CO2ER activity and selectivity along with its competing hydrogen evolution reaction (HER). In addition to the catalyst and reactor design, electrolyte has also a significant impact on the interface. Herein, electrolyte additives were used to modify the local environment around the Cu catalyst during CO2ER. To this purpose, 10mM of ionic additives with bis(trifluoromethylsulfonyl)imide ([NTF2]-) and dicyanamide ([DCA]-) as anions and 1-butyl-3-methylimidazolium ([BMIM]+), potassium (K+), or sodium (Na+) as cations have been added to an aqueous potassium bicarbonate solution (0.1 M KHCO3). COMSOL Multiphysics was also used to calculate the local pH and CO2 concentration at electrode-electrolyte interface in different electrolytes. Results showed that the local environment modifications by the electrolyte additives altered the activity and selectivity of Cu in CO2ER. It was found that the CO2ER activity at -0.92 V was enhanced when using anion with high CO2 affinity and high hydrophobicity such as [NTF2]–. Among [NTF2]–-based additives, [BMIM][NTF2] had a higher faradaic efficiency (FE) for formate (38.7%) compared to K[NTF2] (23.2%) and Na[NTF2] (18.5%) at -0.92 V likely due to the presence of imidazolium cation which can further stabilize the intermediates on the surface and enhance CO2ER. Electrolytes containing [DCA]–-based additives with high hydrophilicity and low CO2 affinity had a very high HER selectivity (>90% FEH2) and low CO2ER selectivity regardless of the cation nature. This observation is attributed to the presence of hydrophilic [BMIM][DCA] in the vicinity of the catalyst which impacts the microenvironment around the catalyst. We observed that [DCA]– anions have a high affinity to adsorb on Cu catalysts as soon as the catalyst is submerged in the electrolyte. Although FTIR showed that [DCA]– anions desorb from the surface at negative potentials, it is likely that [DCA]– anions still remain in the proximity of the electrode, next to the adsorbed cations, impacting the transport of H2O and CO2, and altering the product selectivity. COMSOL calculations showed that the local pH is directly proportional to the H2 evolution activity. Also, hydrophilic salts such as those with the [DCA]– anion had a more alkaline local pH which leads to a lower CO2 concentration in the vicinity of the catalyst. 
    more » « less
  3. ; ; ; ; ; ; (, Journal of The Electrochemical Society)
    Aqueous Li-ion batteries (ALIBs) are an important class of battery chemistries owing to the intrinsic non-flammability of aqueous electrolytes. However, water is detrimental to most cathode materials and could result in rapid cell failure. Identifying the degradation mechanisms and evaluating the pros and cons of different cathode materials are crucial to guide the materials selection and maximize their electrochemical performance in ALIBs. In this study, we investigate the stability of LiFePO4(LFP), LiMn2O4(LMO) and LiNi0.8Mn0.1Co0.1O2(NMC) cathodes, without protective coating, in three different aqueous electrolytes, i.e., salt-in-water, water-in-salt, and molecular crowding electrolytes. The latter two are the widely reported “water-deficient electrolytes.” LFP cycled in the molecular crowding electrolyte exhibits the best cycle life in both symmetric and full cells owing to the stable crystal structure. Mn dissolution and surface reduction accelerate the capacity decay of LMO in water-rich electrolyte. On the other hand, the bulk structural collapse leads to the degradation of NMC cathodes. LMO demonstrates better full-cell performance than NMC in water-deficient aqueous electrolytes. LFP is shown to be more promising than LMO and NMC for long-cycle-life ALIB full cells, especially in the molecular crowding electrolyte. However, none of the aqueous electrolytes studied here provide enough battery performance that can compete with conventional non-aqueous electrolytes. This work reveals the degradation mechanisms of olivine, spinel, and layered cathodes in different aqueous electrolytes and yields insights into improving electrode materials and electrolytes for ALIBs. 
    more » « less
  4. ; ; (, ECS Meeting Abstracts)
    Na-ion batteries have taken more interest in recent years as an alternative battery chemistry to Li-ion batteries because of material abundance, cost, and sufficient volumetric energy density for large-scale energy storage applications. However, Na-ion batteries suffer from rapid capacity fade associated with chemo-mechanical instabilities such as the formation of resistive solid-electrolyte / cathode-electrolyte interphase (SEI/CEI) layers, irreversible phase formations, and particle fracture. The cathode materials are fragile, especially metal oxides, therefore Na-ion cathodes are more prone to mechanical deformations upon larger volumetric expansions/reductions during Na-ion intercalation. Electrolyte additives have been utilized to improve the electrochemical performance of Li-ion and Na-ion batteries by modifying the chemistry of the SEI layers. In situ stress measurements on Si anode in Li-ion batteries demonstrated the generation of less mechanical deformations in the electrode when cycled in the presence of FEC additives.1However, there is not much known about the impact of electrolyte additives on the chemo-mechanical properties of CEI layers in Na-ion battery cathodes. Furthermore, the question still stands about how the electrolyte additives may impact the mechanical stability of the Na-ion cathodes. To address this gap, we systematically investigated the role of FEC additives on the electrochemical performance and associated chemo-mechanical instabilities in NaCrO2 cathodes. Experiments were performed in organic electrolytes with/without FEC additives. First, the talk will start with presenting the impact of FEC additives on the capacity retention and cyclic voltammeter profiles of NaCrO2 cathodes. Then, digital image correlation and multi-beam optical stress sensor techniques were employed to probe electrochemical strain and stress generation in the composite NaCrO2 cathodes during electrochemical cycling in organic electrolytes with/without FEC additives. Surface chemistry of the NaCrO2 cathodes after cycling was investigated with the FT-IR measurements. In summary, the talk will present contrast differences in the electrochemical and chemo-mechanical properties of NaCrO2 cathodes when cycled in the presence of the FEC additives. Acknowledgement: This work is supported by National Science Foundation (award number 2321405). Reference: 1) Tripathi et al 2023 J. Electrochem. Soc. 170 090544 
    more » « less
  5. ; ; ; ; ; (, Batteries)
    Aqueous sodium-ion batteries (ASIBs) represent a promising battery technology for stationary energy storage, due to their attractive merits of low cost, high abundance, and inherent safety. Recently, a variety of advanced cathode, anode, and electrolyte materials have been developed for ASIBs, which not only enhance our fundamental understanding of the Na insertion mechanism, but also facilitate the research and development of practical ASIB systems. Among these electrode materials, iron-based materials are of particular importance because of the high abundance, low price, and low toxicity of Fe elements. However, to our knowledge, there are no review papers that specifically discuss the properties of Fe-based materials for ASIBs yet. In this review, we present the recent research progress on Fe-based cathode/anode materials, which include polyanionic compounds, Prussian blue, oxides, carbides, and selenides. We also discuss the research efforts to build Fe-based ASIB full cells. Lastly, we share our perspectives on the key challenges that need to be addressed and suggest alternative directions for aqueous Na-ion batteries. We hope this review paper can promote more research efforts on the development of low-cost and low-toxicity materials for aqueous battery applications. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email