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Results for “Solid electrolyte interphase”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 559 records · Page 31
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

Achieving carbon-rich silicon-containing ceramic anode for advanced lithium ion battery

Silicon carbon (Si/C) materials are promising anode candidates for high performance lithium ion batteries (LIBs). However, serious volume expansion and solid electrolyte interface formation limited their actual capacity during lithiation and delithiation. In the present study, an innovative and low-cost synthetic approach was developed for synthesizing carbon-rich silicon-containing polymer-derived ceramics from poly(dimethylsilyene)diacetylenes (PDSDA) and its feasibility to be used as anodes was demonstrated. The attained PDCs@800 °C exhibited a high specific capacity upto 883 mAhg -1 at 400 mAg -1 , with >99% coulombic efficiency (CE), and 90% capacity retention even after 500 cycles, setting a new record for PDCanode materials in LIBs. The high specific capacity was attributed to the incessant Si/C network which delivered consistent conductance and a stable solid electrolyte interphase (SEI). Here, this study opens the door to explore and apply well-designed ceramic materials derived from tailored polymers as high performance anodes for lithium ion batteries.

25 ENERGY STORAGE↗
DOE OSTI2026

Tailored Solvent Treatment for Optimized Production of Upcycled Anodes from End-Of-Life Li-Ion Batteries

Recycling processes for lithium-ion batteries typically overlook graphite because of its lower market value relative to that of transition-metal-containing cathode materials. However, graphite recovered from cycled lithium-ion batteries holds additional engineered value associated with the solid-electrolyte interphase (SEI). The SEI contributes critical electronic passivation of the graphite surface but becomes highly resistive with extended cycling, yielding poor cell performance. In this work, we apply tailored solvent treatment to end-of-life (EOL) graphite anodes to selectively remove adverse SEI components while retaining beneficially passivating species. We evaluate a series of polar protic solvents to achieve targeted removal of SEI components and control selectivity through rational variation in solvent properties. The physiochemical properties of treatment solvents correlate with both the retained SEI composition and the corresponding electrochemical performance of solvent-treated “upcycled” graphite anodes. Within the initial set of solvents evaluated, top-performing candidates show capacity and Coulombic efficiency nearly equivalent to those of an analogous pristine anode, as well as promising electrochemical performance enhancement with regard to irreversible capacity-loss metrics. This study establishes critical design principles for an optimized anode upcycling method that enhances the value of recycled graphite by retaining and upgrading the SEI.

25 ENERGY STORAGE↗
DOE OSTI2023

In situ probing the origin of interfacial instability of Na metal anode

The unstable and fragile solid electrolyte interphase (SEI) has restricted the application of Na metal anodes. Despite numerous research efforts being put into understanding its chemical composition and physical properties, direct observation of its formation remains a challenge due to the lack of temporal and spatial resolution. Here, through combined in situ probing techniques, we exhibit two pivotal stages associated with SEI instability during the often -neglected formation process. It is revealed that Na metal that is not uniformly passivated at the initial (passivating) stage will trigger unrestricted electrolyte decomposition and homogeneous components distribution during the subsequent (growing) stage. SEI with homogenously distributed components is found to have higher solubility than that with a layered structure evolved from a compact passivation layer. Furthermore, through demonstrating an SEI dissolution model that is closely related to its formation process and compositional distribution, this work sheds light on an uncharted territory of Na metal batteries.

25 ENERGY STORAGE↗
DOE OSTI2018

Calendar-life versus cycle-life aging of lithium-ion cells with silicon-graphite composite electrodes

The use of blended silicon-graphite (Si-Gr) negative electrodes increases the energy density of lithium-ion cells over those containing only graphite (Gr) electrodes. However, volume changes in the Si particles that occur during cycling causes deterioration of the solid-electrolyte interphase (SEI) layer on the particles resulting in further electrolyte reduction that immobilizes Li+ ions and, therefore, capacity fade. Because the volume changes are not expected to occur during a potentiostatic hold (referred to as calendar-life aging), by comparison of cycle-life and calendar-life aged cells one can expect to assess the role of volume changes in the deterioration of cell performance. To this end, cells with Si-Gr and Gr negative electrodes (and Li 1.03 (Ni 0.5 Co 0.2 Mn 0.3 ) 0.97 O 2 containing positive electrodes) were assembled, tested, and compared using cycle-life and calendar-life aging protocols. As expected, the capacity loss of the cycle-life aged cells was higher than that of the calendar-life aged cells. However, the measurable capacity loss for the calendar-life aged cells indicated continued immobilization of Li + ions. Furthermore, electrolytes extracted from the calendar-life aged cells showed more LiPF 6 hydrolysis products than those extracted from the cycle-life aged cells. In conclusion, we discuss possible mechanistic causes for the observed aging behaviors in this article.

25 ENERGY STORAGE↗
DOE OSTI2020

Interface stability of LiCl-rich argyrodite Li 6 PS 5 Cl with propylene carbonate boosts high-performance lithium batteries

In solid-state lithium (Li)-metal batteries (SSLMBs), sulfide-based Li-ion conductors represent one of the most popular solid electrolytes (SEs). However, the development of sulfide-based SSLMBs is significantly hampered by interfacial issues including large solid-solid contact resistance and serious side reactions at the SE/electrode interface. To address these issues, here, we demonstrated a simple and efficient strategy by using LiCl-rich argyrodite Li 6 PS 5 Cl (Li 6 PS 5 Cl-LiCl) SE and trace amount of propylene carbonate (PC) at the SE/electrode interface to facilitate the formation of stable and robust solid electrolyte interphase (SEI). Additionally, the formed SEI not only serves as a buffer layer to passivate the interfacial reactions and suppress Li dendrite growth, but also acts as a bridge for Li-ion conduction to reduce the contact resistance. As a result, the Li||Li symmetric cell exhibited long-term electrochemical cycling stability over 1000 h at a current density of 0.2 mA cm -2 . Furthermore, the assembled Li||Li 4 Ti 5 O 12 (LTO) batteries delivered a specific capacity of 175 mAh g–1 at 0.2 C, and remained an excellent specific capacity of 116 mAh g –1 after 200 cycles at a high current rate of 1 C. These features indicate a feasible strategy to enhance the interfacial property of high-performance SSLMBs.

25 ENERGY STORAGE↗
DOE OSTI2021

Significant life extension of lithium-ion batteries using compact metallic lithium reservoir with passive control

Both traditional graphite-based lithium-ion batteries and next generation silicon-based chemistries suffer significant capacity fade from loss of cyclable lithium due to continued solid-electrolyte interphase growth. A possible engineering solution to maintaining the capacity of cells is incorporating a metallic lithium reservoir and discharging the reservoir into a working electrode to make up for lost cyclable lithium. Here, metallic lithium reservoirs are inserted into both pouch- and cylindrical-format cells. Significant capacity recovery and lifetime extension are demonstrated for traditional graphite and Si/graphite-based cells. In this work, a combination of post-mortem characterization and modeling provide insight into how the lithium distribution as a function of position from reservoir vary with recovery rate. The potential of using passive control to potentially eliminate the need for extra wiring for the third electrode is explored using a simple resistor.

25 ENERGY STORAGE↗
DOE OSTI2021

Combined density functional theory/kinetic Monte Carlo investigation of surface morphology during cycling of Li-Cu electrodes

In this work, we employed a combined density functional theory and kinetic Monte Carlo approach in order to investigate the nanoscale behavior of lithium stripping and plating on lithium-copper nanoalloys. Density functional theory calculations were used to develop an atom-by-atom understanding of the nucleation behavior of lithium on copper surfaces with different surface morphologies. We found that nanometric pits resulted in significantly more favorable lithium deposition when compared to pristine or lightly-defective Cu surfaces, which is in agreement with previous experimental studies. We then used density functional theory and constrained ab initio molecular dynamics to develop interaction and reaction parameters for a larger-scale kinetic Monte Carlo model in order to provide insight into the stripping and plating behavior of nanostructured Li-Cu nanoalloy anodes. Substantial losses in capacity and strong indications of morphological change were observed for a wide range of Cu:Li ratios over 100 cycles. We observed a complex relationship between the nanoparticle composition and the properties of the formed solid-electrolyte interphase.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2018

The synergetic interaction between $\mathrm{LiNO_3}$ and lithium polysulfides for suppressing shuttle effect of lithium-sulfur batteries

LiNO 3 has been widely used as an effective electrolyte additive in lithium-sulfur (Li-S) batteries to suppress the polysulfide shuttle effect. To better understand the mechanism of suppressed shuttle effect by LiNO3, herein we report a comprehensive investigation of the influence of LiNO 3 additive on the formation process of the solid electrolyte interphase (SEI) layer on lithium anode of Li-S batteries by operando X-ray absorption spectroscopy (XAS). We observed that a compact and stable SEI layer composed of Li 2 SO 3 and Li 2 SO 4 on top of lithium anode is formed during the initial discharge process due to the synergetic effect of shuttled polysulfides and LiNO 3 , which can effectively suppress the subsequent reaction between polysulfides in electrolyte and lithium metal and thus result in the alleviation of polysulfide shuttle effect. In contrast, when using electrolyte without LiNO 3 , the shuttled polysulfides continuously react with lithium metal to form insulating Li2S on lithium anode, leading to the irreversible capacity loss. Our present operando XAS study provides a valuable insight into the important role of LiNO 3 for the protection of lithium anodes, which will be beneficial for the further development of new electrolyte additives for high-performance Li-S batteries.

25 ENERGY STORAGE↗
DOE OSTI2019

Stress evolution in lithium metal electrodes

The potential advantages of lithium metal anodes have received widespread attention (highest capacity, lowest reduction potential, etc). However, the poor stability of Li metal / liquid electrolyte interfaces leads to chronic problems, such as dendrite formation and capacity loss. The possible impact of mechanical effects on interface stability and dendrite formation are difficult to probe directly. In this study, stress evolution during lithium plating and stripping was monitored with precise in situ measurements. The data obtained with different film thicknesses made it possible to separate the stresses associated with the lithium metal and the solid electrolyte interphase (SEI). The results show that significant stresses are created in the SEI films. Based on this, a basic model of wrinkling-ratcheting-delamination is also presented. This analysis indicates that plasticity in a growing Li film can enhance surface wrinkling, and thus lead to morphological destabilization of a planar growth front.

25 ENERGY STORAGE↗
DOE OSTI2022

A new mechanism of stabilizing SEI of Si anode driven by crosstalk behavior and its potential for developing high performance Si-based batteries

Stabilizing solid electrolyte interphase (SEI) is a key factor for determining cell performance of Silicon (Si) anode, such as safety, cycle lifetime, and calendar lifetime. Here, we found a new potential for stabilizing SEI of the Si anode, driven by crosstalk with cathode material. Here we investigated the effect of crosstalk on the chemistry of SEI of the Si anode as a function of three different, representative cathode materials: LiNi 0.5 Mn 0.3 Co 0.2 O 2 (NMC532), LiNi 0.8 Mn 0.1 Co 0.1 O 2 (NMC811), and LiFePO 4 (LFP). Specifically, we observed that crosstalk significantly affected the formation and growth mechanism of SEI layer on the Si anodes. Unexpectedly, dissolved Fe ions from the LFP cathode has a positive impact on the chemistry and electrochemical stability of the SEI layer of Si anode compared to the other cathodes, resulting in better electrochemical performance in terms of initial coulombic efficiency and capacity fade.

25 ENERGY STORAGE↗
DOE OSTI2021

Effects of short-term over-discharge cycling on the performance of commercial 21,700 lithium-ion cells and the identification of degradation modes

In this paper, short-term over-discharge cycling was performed on commercially available 21,700 lithium-ion cells to investigate its effects on cell performance; the degradation modes were also identified and analyzed in detail using both in-situ and ex-situ methods. Results show that observable capacity loss occurs when the cell is over-discharged to 112.5% depth of discharge. Moreover, the negative impact of the depth of discharge on cell performance (or cell aging) is more serious than the number of cycles, and continuous over-discharge cycling will accumulate such impact. The loss of Li inventory related to the decomposition and reformation of solid electrolyte interphase film is an important cause of the irreversible capacity loss/degradation of Li-ion cells during over-discharge cycling testing. Furthermore, the dissolution of copper current collector can greatly reduce the mechanical stability of the anode, and further, the deposition of Cu, the exfoliation and the cracking of active material particles can influence the transfer of ions and lead to the loss of Li inventory and the loss of active material within Li-ion cells. Additionally, when the depth of discharge exceeds 108.3%, deposition of Cu is observed on the ceramic-covered side of separators.

25 ENERGY STORAGE↗
DOE OSTI2021

A control oriented comprehensive degradation model for battery energy storage system life prediction

In order to ensure that stationary battery energy storage systems (BESSs) provide reliable energy buffering, both for power quality and economic purposes, the degradation must be considered. Cell degradation involves various side reactions and is highly dependent on its operating conditions. To accurately track cell degradation and predict its impact on battery behavior, a comprehensive physics-based degradation model based on an electrolyte phase-enhanced single particle (SP) model is developed. Key degradation physics, namely solid electrolyte interphase (SEI) layer formation and growth, Li plating on the graphite anode, and Mn dissolution on cathode of nickel-cobalt-manganese oxide (NMC622) are considered. The model is validated against experimental capacity data. The results reveal that the deposition rate of both SEI layer and Li metal increase as the charge voltage increases. At the cathode side, the solvent oxidation rate determines the Mn dissolution rate. As a result, the volume fraction of NMC622 in the cathode continually decreases at a gradually increasing rate.

25 ENERGY STORAGE↗
DOE OSTI2024

Lithiophilic CoF 2 @C hollow spheres towards spatial lithium deposition for stable lithium metal batteries

Lithium metal (LM) is a promising anode for next-generation batteries due to its high theoretical capacity and low electrode potential. Nonetheless, side reactions, volume change, and unwanted lithium dendrite growth seriously limit the practical application of LM. Herein, with the aid of a hard template approach, a novel lithiophilic CoF 2 -carbon hollow sphere (CoF 2 @C-HS) composite material is successfully prepared via a facile in-situ fluorination and etching strategy. The lithiophilic CoF 2 acts as nucleation sites to reduce nucleation overpotential as well as induces the spatial Li deposition and the formation of LiF-rich solid electrolyte interphase (SEI), and the hollow carbon matrix can enhance the electrical conductivity and offer free space for LM deposition. Theoretical simulations reveal that the synergistic effect of lithiophilic CoF 2 and hollow carbon matrix homogenizes the electric field distribution and Li + flux. Benefiting from these advantages, the CoF 2 @C-HS-modified copper substrate electrode delivers an enhanced Coulombic efficiency (CE) of 93.7% for 280 cycles at 1 mA cm –2 and 1 mA h cm –2 . The symmetrical cell using CoF 2 @C-HS can stably cycle more than 1800 h with a low voltage hysteresis of 11 mV at a current density of 0.5 mA cm –2 and an areal capacity of 0.5 mA h cm –2 . Moreover, the Li@CoF 2 @C-HS composite anode enables more than 300 stable cycles at 1 C with a capacity retention of 95% in LiFePO 4 -based full cell and 110 stable cycles at 1 C in LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811)-based high-voltage full cell. Finally, this work might shed a new light on designing lithiophilic hosts to spatially confine LM deposition, realizing dendrite-free LM anodes and the practical applications of LM batteries.

25 ENERGY STORAGE↗
DOE OSTI2020

Anode-free, Lean-Electrolyte Lithium-Sulfur Batteries Enabled by Tellurium-Stabilized Lithium Deposition

For realizing practically viable lithium-sulfur (Li-S) batteries, it is imperative to stabilize Li deposition and improve cyclability while reducing excess Li and electrolyte. We have discovered that introducing tellurium (Te) into the Li-S system as a cathode additive significantly improves the reversibility of Li plating and stripping by forming a tellurized and sulfide-rich solid-electrolyte interphase (SEI) layer on the Li surface. A remarkable improvement in cyclability is demonstrated in anode-free full cells with limited Li inventory and large-area Li-S pouch cells under lean electrolyte conditions. Tellurium reacts with polysulfides to generate soluble polytellurosulfides that migrate to the anode side and form stabilizing lithium thiotellurate and lithium telluride in situ as SEI components. A significant reduction in electrolyte decomposition on the Li surface is also engendered. This work demonstrates Te inclusion as a viable strategy for stabilizing Li deposition and establishes a robust evaluation framework for preserving electrochemical performance under limited Li and limited electrolyte conditions.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Battery aging mode identification across NMC compositions and designs using machine learning

A comprehensive understanding of lithium-ion battery (LiB) lifespan is the key to designing durable batteries and optimizing use protocols. Although battery lifetime prediction methods are flourishing, diagnosis of the root causes of aging and degradation have not yet been well developed nor studied for a broad mixture of designs and use cases. Here, we create a machine-learning (ML)-based framework that distinguishes aging modes using multiple electrochemical signatures recorded cycle-by-cycle. The predominant aging behaviors include a combination of loss of active materials in cathode (LAMPE) and a loss of Li inventory (LLI) in Li plating or solid electrolyte interphase (SEI) formation, manifested from 44 batteries representing two cathode chemistries, two electrode loadings, and five charging rates. Here, the aging mode classification accuracy is 86% using features within the first 50 cycles and increases to 88% beyond 225 cycles. The same features can quantify the percentage of end-of-life LAMPE with only 4.3% of error.

25 ENERGY STORAGE↗