iMechanica - lithium ion batteries
https://imechanica.org/taxonomy/term/6571
enUsing Thermodynamic State Index axis for Battery Aging
https://imechanica.org/node/24616
<div class="field field-name-taxonomy-vocabulary-6 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/76">research</a></div></div></div><div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/11046">battery</a></div><div class="field-item odd"><a href="/taxonomy/term/6571">lithium ion batteries</a></div><div class="field-item even"><a href="/taxonomy/term/6246">lithium ion battery ·lithiation induced strain · charging rate · coating · tin oxide · in situ transmission electron microscopy</a></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>There is a new paper in predicting battery aging without testing based empirical models. "<span class="title-text">Entropy generation model to estimate battery aging"</span></p>
<p><a href="https://www.sciencedirect.com/science/article/abs/pii/S2352152X20315772?via%3Dihub">https://www.sciencedirect.com/science/article/abs/pii/S2352152X20315772?...</a></p>
<p><a href="https://www.linkedin.com/feed/update/urn:li:activity:6713844072907321344/">https://www.linkedin.com/feed/update/urn:li:activity:6713844072907321344/</a></p>
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</div></div></div>Wed, 23 Sep 2020 17:49:40 +0000Cemal Basaran24616 at https://imechanica.orghttps://imechanica.org/node/24616#commentshttps://imechanica.org/crss/node/24616Effect of cobalt content on the electrochemical properties and structural stability of NCA type cathode materials
https://imechanica.org/node/22609
<div class="field field-name-taxonomy-vocabulary-6 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/76">research</a></div></div></div><div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/7390">Atomistic Computer Modeling of Materials</a></div><div class="field-item odd"><a href="/taxonomy/term/11931">DFT calculations</a></div><div class="field-item even"><a href="/taxonomy/term/4041">cathode material</a></div><div class="field-item odd"><a href="/taxonomy/term/6571">lithium ion batteries</a></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p><strong><span> <span><a href="http://pubs.rsc.org/en/content/articlelanding/2014/CP/C8CP03237H#!divAbstract" target="_blank">Effect of cobalt content on the electrochemical properties and structural stability of NCA type cathode materials</a></span></span></strong></p>
<p> <span><strong><span><a href="http://pubs.rsc.org/en/content/articlelanding/2014/CP/C8CP03237H#!divAbstract" target="_blank">Physical Chemistry Chemical Physics (PCCP)</a> </span></strong></span></p>
<p><span> <em><span>Please email me if you want the PDF copy (PCCP Article Sharing Policy)</span></em></span></p>
<p><strong><span><span> Abstract: </span></span></strong><span>At present, the most common type of cathode materials, NCA (Li<span class="s1">1-x</span>Ni<span class="s1">0.80</span>Co<span class="s1">0.15</span>Al<span class="s1">0.05</span>O<span class="s1">2</span>, x = 0 to 1), </span><span>have a very high concentration of cobalt. Since cobalt is toxic and expensive, the existing design of </span><span>cathode materials is neither cost-effective nor environmentally benign. We have performed density </span><span>functional theory (DFT) calculations to investigate electrochemical, electronic, and structural properties </span><span>of four types of NCA cathode materials with the simultaneous decrease in Co content along with the </span><span>increase in Ni content. Our results show that even if the cobalt concentration is significantly decreased </span><span>from 16.70% (NCA_I) to 4.20% (NCA_IV), variation in intercalation potential and specific capacity is not </span><span>significant. For example, in the case of 50% Li concentration, the voltage drop is only B17% while the </span><span>change in specific capacity is negligible. Moreover, we have also explored the influence of sodium </span><span>doping in the intercalation site on the electrochemical, electronic, and structural properties. By </span><span>considering two extreme cases of NCAs (i.e., with highest and lowest Co content: NCA_I and NCA_IV, </span><span>respectively), we have demonstrated the importance of Na doping from the structural and electronic </span><span>point of view. Our results provide insight into the design of environmentally benign, low-cost cathode </span><span>materials with reduced cobalt concentration.</span></p>
<p><span><span>* <em>We started this work after a stimulating discussion session with the researchers at the <a href="https://www.tesla.com/">Tesla Motors </a>Headquarter, Palo Alto, California. </em></span><em><span>If you are interested in this topic, you may want to read the latest development at Tesla on NCA Cathode Materials. </span></em></span></p>
<p><span><strong><a href="https://electrek.co/2018/05/03/tesla-model-3-battery-cells-rare-data-energy-density-cobalt/" target="_blank"><em>Tesla releases rare details about Model 3’s battery cells, claims highest energy density and less cobalt</em></a></strong></span></p>
<p><span><em> <strong><a href="https://cleantechnica.com/2018/05/13/teslas-next-generation-cathodes-a-victory-for-human-rights-advocates-against-drcs-artisanal-mining/" target="_blank">Tesla’s Next-Generation Cathodes A Victory For Human Rights Advocates Against DRC’s “Artisanal Mining”</a></strong></em></span></p>
<p><span> <img src="https://pbs.twimg.com/media/DkuZsSeXsAE9ALB.jpg" alt="" height="247" data-aria-label-part="" /></span></p>
<p><span> Thanks, </span></p>
<p><span> <a href="http://dibakardatta.com/" target="_blank">Dibakar Datta</a></span></p>
<p><span> Email - dibakar.datta[AT]njit.edu</span></p>
</div></div></div>Tue, 28 Aug 2018 17:22:32 +0000Dibakar Datta22609 at https://imechanica.orghttps://imechanica.org/node/22609#commentshttps://imechanica.org/crss/node/22609Rate-dependent stress evolution in nanostructured Si anodes upon lithiation
https://imechanica.org/node/20490
<div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/967">viscoplasticity</a></div><div class="field-item odd"><a href="/taxonomy/term/6571">lithium ion batteries</a></div><div class="field-item even"><a href="/taxonomy/term/8479">silicon anode</a></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p><a href="http://zhengjia.weebly.com/">Zheng Jia</a>, Wing Kam Liu, Rate-dependent stress evolution in nanostructured Si anodes upon lithiation, Applied Physics Letters, 109, 163903 (2016) (DOI:<a href="http://dx.doi.org/10.1063/1.4964515">http://dx.doi.org/10.1063/1.4964515</a>)</p>
<p><img src="http://zhengjia.weebly.com/uploads/2/4/2/9/24290020/20_5_orig.png" alt="" width="564" height="267" /></p>
<p>Development of stresses and fracture in Si-based anodes for lithium-ion batteries are strongly affected by lithiation-induced plasticity. Recent experiments indicate that the nature of plasticity of lithiated silicon is rate-dependent. We establish a theoretical model to capture the viscoplastic mechanical behavior of Si anodes during two-phase lithiation. It is demonstrated that the lithiation-induced stress field is determined by the migration speed of the Li-Li3.75 Si interface and the characteristic size of the Si anodes. If experimentally measured interface velocity data in Si nanoparticle is available, the mechanistic model can directly predict the rate-sensitive spatiotemporal stress profile, which is hardly measured in experiments.</p>
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<tr class="odd"><td><span class="file"><img class="file-icon" alt="PDF icon" title="application/pdf" src="/modules/file/icons/application-pdf.png" /> <a href="https://imechanica.org/files/Rate-dependent%20stress%20evolution%20in%20nanostructured%20Si%20anodes%20upon%20lithiation.pdf" type="application/pdf; length=1483263">Rate-dependent stress evolution in nanostructured Si anodes upon lithiation.pdf</a></span></td><td>1.41 MB</td> </tr>
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</div></div></div>Thu, 20 Oct 2016 05:05:39 +0000Zheng Jia20490 at https://imechanica.orghttps://imechanica.org/node/20490#commentshttps://imechanica.org/crss/node/20490Time-dependent deformation behavior of polyvinylidene fluoride binder: Implications on the mechanics of composite electrodes
https://imechanica.org/node/20379
<div class="field field-name-taxonomy-vocabulary-6 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/76">research</a></div></div></div><div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/17">thin film</a></div><div class="field-item odd"><a href="/taxonomy/term/6571">lithium ion batteries</a></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p><span>Time-dependent deformation behavior of polyvinylidene fluoride binder: Implications on the mechanics of composite electrodes (<a href="http://www.sciencedirect.com/science/article/pii/S0378775316312721">http://www.sciencedirect.com/science/article/pii/S0378775316312721</a>)</span>
</p><p><strong>Arnuparp Santimetaneedol, Rajasekhar Tripuraneni, Shawn A. Chester, <span>Siva P.V. Nadimpalli </span></strong></p>
<p>The majority of existing battery models that simulate composite electrode behavior assume the binder as a linear elastic material due to lack of a thorough understanding of time-dependent mechanical behavior of binders. Here, thin films of polyvinylidene fluoride binder, prepared according to commercial battery manufacturing method, are subjected to standard monotonic, load-unload, and relaxation tests to characterize the time-dependent mechanical behavior. The strain in the binder samples is measured with the digital image correlation technique to eliminate experimental errors. The experimental data showed that for (charging/discharging) time scales of practical importance, polyvinylidene fluoride behaves more like an elastic-viscoplastic material as opposed to a visco-elastic material; based on this observation, a simple elastic-viscoplastic model, calibrated against the data is adopted to represent the deformation behavior of binder in a Si-based composite electrode; the lithiation/delithiation process of this composite was simulated at different C rates and the stress/strain behavior was monitored. It is observed that the linear elastic assumption of the binder leads to inaccurate results and the time-dependent constitutive behavior of the binder not only leads to accurate prediction of the mechanics but is an essential step towards developing advanced multi-physics models for simulating the degradation behavior of batteries.</p>
</div></div></div>Thu, 29 Sep 2016 04:42:30 +0000Siva P V Nadimpalli20379 at https://imechanica.orghttps://imechanica.org/node/20379#commentshttps://imechanica.org/crss/node/20379High damage tolerance of electrochemically lithiated silicon
https://imechanica.org/node/18891
<div class="field field-name-taxonomy-vocabulary-6 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/76">research</a></div></div></div><div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/6571">lithium ion batteries</a></div><div class="field-item odd"><a href="/taxonomy/term/32">fracture mechanics</a></div><div class="field-item even"><a href="/taxonomy/term/8479">silicon anode</a></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>Wang, X. et al. High damage tolerance of electrochemically lithiated silicon. Nature Communications 6:8417 doi: 10.1038/ncomms9417 (2015).</p>
<p><strong>Abstract</strong></p>
<p>Mechanical degradation and resultant capacity fade in high-capacity electrode materials critically hinder their use in high-performance rechargeable batteries. Despite tremendous efforts devoted to the study of the electro–chemo–mechanical behaviours of high-capacity electrode materials, their fracture properties and mechanisms remain largely unknown. Here we report a nanomechanical study on the damage tolerance of electrochemically lithiated silicon. Our in situ transmission electron microscopy experiments reveal a striking contrast of brittle fracture in pristine silicon versus ductile tensile deformation in fully lithiated silicon. Quantitative fracture toughness measurements by nanoindentation show a rapid brittle-to-ductile transition of fracture as the lithium-to-silicon molar ratio is increased to above 1.5. Molecular dynamics simulations elucidate the mechanistic underpinnings of the brittle-to-ductile transition governed by atomic bonding and lithiation-induced toughening. Our results reveal the high damage tolerance in amorphous lithium-rich silicon alloys and have important implications for the development of durable rechargeable batteries.</p>
<p><a href="http://www.nature.com/ncomms/2015/150924/ncomms9417/full/ncomms9417.html">http://www.nature.com/ncomms/2015/150924/ncomms9417/full/ncomms9417.html</a></p>
<p><a href="http://www.news.gatech.edu/2015/09/24/nano-mechanical-study-offers-new-assessment-silicon-next-gen-batteries">http://www.news.gatech.edu/2015/09/24/nano-mechanical-study-offers-new-a...</a></p>
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<tr class="odd"><td><span class="file"><img class="file-icon" alt="PDF icon" title="application/pdf" src="/modules/file/icons/application-pdf.png" /> <a href="https://imechanica.org/files/ncomms9417.pdf" type="application/pdf; length=1904692">ncomms9417.pdf</a></span></td><td>1.82 MB</td> </tr>
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</div></div></div>Thu, 24 Sep 2015 21:04:21 +0000Shuman_Xia18891 at https://imechanica.orghttps://imechanica.org/node/18891#commentshttps://imechanica.org/crss/node/18891In-situ TEM Observation of Pulverization of Al Nanowires and Evolution of Surface Al2O3 During Lithiation-Delithiation Cycles
https://imechanica.org/node/10997
<div class="field field-name-taxonomy-vocabulary-6 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/76">research</a></div></div></div><div class="field field-name-taxonomy-vocabulary-8 field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/6568">pulverization</a></div><div class="field-item odd"><a href="/taxonomy/term/6569">Al2O3 coating</a></div><div class="field-item even"><a href="/taxonomy/term/6570">Al nanowires</a></div><div class="field-item odd"><a href="/taxonomy/term/6571">lithium ion batteries</a></div><div class="field-item even"><a href="/taxonomy/term/6574">atomic layer deposition (ALD)</a></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>
<a href="http://pubs.acs.org/doi/abs/10.1021/nl202088h">Nano Lett. <strong>DOI: </strong>10.1021/nl202088h</a>
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<p>
Lithiation-delithiation cycles of individual aluminum nanowires (NWs) with naturally oxidized Al2O3 surface layers (thickness 4-5 nm) were conducted in situ in a transmission electron microscope (TEM). Surprisingly, the lithiation was always initiated from the surface Al2O3 layer, forming a stable Li-Al-O glass tube with a thickness of about 6-10 nm wrapping around the Al NW core. After lithiation of the surface Al2O3 layer, lithiation of the inner Al core took place, which converted the single crystal Al to a poly-crystalline LiAl alloy, with a volume expansion of about 100%. The Li-Al-O glass tube survived the 100% volume expansion, by enlarging through elastic and plastic deformation, acting as a solid electrolyte with exceptional mechanical robustness and ion conduction. Voids were formed in the Al NWs during the initial delithiation step and grew continuously with each subsequent delithiation, leading to pulverization of the Al NWs to isolated nanoparticles confined inside the Li-Al-O tube. There was a corresponding loss of capacity with each delithiation step when arrays of NWs were galvonostatically cycled. The results provide important insight into the degradation mechanism of lithium-alloy electrodes and into recent reports about the performance improvement of lithium ion batteries (LIBs) by atomic layer deposition of Al2O3 onto the active materials or electrodes.
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</div></div></div>Mon, 29 Aug 2011 20:39:50 +0000Jianyu Huang10997 at https://imechanica.orghttps://imechanica.org/node/10997#commentshttps://imechanica.org/crss/node/10997Error | iMechanica