bluuebunny/crossref_metadata_2025_split huggingface dataset:
In Situ Controlled Syntheses of Electrolyte Additives for High Voltage Lithium Ion Batteries
Authors: Liao Chen , Yang Jianzhong , Shkrob Ilya A , Zhang Zhengcheng , Gutierrez Arturo , Croy Jason R. 
Published: February 2020

The development of cathode materials needs concomitant electrolyte developments to accommodate the high voltage to reach high energy and power densities required for electric vehicle and personal electronics. Previously we reported that aging TMSPi (trimethylsilylphosphite) additive in a standard 1.2 M LiPF6 carbonate electrolyte can generate a beneficial transient product, PF2(OSi(CH3)3), which was later proven to mitigate impedance rise during long term cycling in composite cathode-graphite cells. However, the generation of PF2(OSi(CH3)3) is spontaneous and cannot be controlled, and as aging process proceeds to a greater extent, PF2(OSi(CH3)3) disappears gradually and other transient detrimental products form along the way and eventually deteriorate the impedance.1,2

By using molecular engineering to tune functionality, ratio, and stability, we can control the in situ electrolyte additive to selectively synthesize the beneficial component in high yield (> 98%) and maximize the battery performance. The in situ method is particularly of interest to scale up electrolyte preparation since it would alleviate any requirements of extra separation and purification of the desired additives. By varying the structure of the additive precursor, we clearly see a trend that is governed by thermodynamics which determine the product ratio and composition. The electrochemistry of these additives and their application in composite cathodes will be discussed. By introducing the novel in situ synthetic method for electrolyte additive syntheses, avenues for new additives that were previously inaccessible will open up and facilitate the development of the lithium ion batteries toward high energy and high power density.
References

The Journal of Physical Chemistry C 2018, 122 (18), 9811-9824.

RSC Advances 2016, 6 (44), 38342-38349.
Sulfur Incorporated into Carbon Coated FeS2 Nanotubes for High-Performance Lithium-Sulfur Batteries
Authors: Zeng Zhipeng , Liu Xingbo 
Published: February 2020

The high theoretical capacity (1672 mAh g-1) and energy density (2600 W h kg-1) for sulfur electrode make it be a very promising candidate for electric and hybrid electric vehicles among the various candidates. However, the practical application of this promising material is still greatly hindered by poor cycle stability and low Coulombic efficiency resulting from the notorious “shuttle effect” of polysulfides. To prevent the diffusion of polysulfides, more attention has been paid to utilize the chemical interactions between the functional groups on the host materials and lithium polysulfides (LiPSs).
The inexpensive, environmentally friendly and high-conductive pyrite-based materials show high catalytic activity in relation to polysulfides. Here, we report carbon coated FeS2 nanotubes as the sulfur host (FeS2@C-S) for Li-S batteries application. The carbon shell can facilitate fast kinetics of conversion between LiPSs and Li2S, resulting in the excellent rate capability. Meanwhile, the hollow space as the major chamber for sulfur storage can effectively accommodate the volume change during the charge/discharge process. In addition, the FeS2 with carbon shell can not only act as barrier layer but also provide strong chemical interaction force to prevent the LiPSs from diffusion. As a result, the FeS2@C-S electrode with unique structure combined physical confinement and chemical bonding to polysulfides exhibited excellent electrochemical performance, in terms of cycle stability, rate capability and Coulombic efficiency, showing the great potential application in developing high-performance Li-S batteries.
Investigating the Effect of Lewis Acid Base Interaction in Non-Stoichiometric Vanadium Oxide Based CNFs in Lithium – Sulfur Battery
Authors: Pai Rahul , Singh Arvinder , Kalra Vibha 
Published: February 2020

Despite the potential of lithium-sulfur batteries to reach practical energy densities of 500–600 Wh/kg, there are still many problems plaguing their development. The sulfur cathode suffers from low electrochemical utilization and poor cycle life owing to the insulating nature of S and the Li2S discharge product, and the shuttling of lithium polysulfide species especially at high areal mass loadings. Enormous progress has been achieved in terms of capacity and static life during the past few years to overcome these issues, by employing various carbon and inorganic materials (metal oxides, metal-organic frameworks). Recently, non-stoichiometric metal oxides have been employed as sulfur host materials due to their high conductivity and ability to bind polysulfides chemically through unsaturated metal ion sites. However, the formation of metal-suboxides involves a high-temperature calcination process, which usually results in dense host materials with lower accessible surface area, and a reduced host/polysulfide interaction. Moreover, these studies are often reported with low sulfur loadings (1–2 mg/cm2) resulting in lower areal capacity.
Herein, we report the use of electrospun vanadium monoxide/carbon nanofibers (VCNFs) as cathode host in Li-S batteries, which provide high electrical conductivity for better sulfur utilization and strong Lewis acid-base interaction with polysulfides to suppress shuttle. The developed cathode possesses hierarchical micro-mesoporous architecture with inter-fiber spacing and a high surface area of 181 m2/g. The unique architecture overcomes the challenges associated with dense, low active surface area based powered oxide materials. The developed VCNFs-S cathodes with a high sulfur loading of 3 mg/cm2 exhibit initial discharge capacities of ∼1350, ∼1247, and ∼1113 mAh g–1 at 0.1, 0.2, and 0.5 C rates, respectively, with long-term cycling (Fig 1a) over 200 cycles at 0.5 C rate. Moreover, at ~7mg/cm2, Li-S cells exhibit high areal capacity of 8 mAh/cm2 at a current density of C/10 up to 50 cycles (Fig 1b). The high surface area results in active reaction sites spread throughout the VCNFs, improving the accessible reaction area for better binding of polysulfides, enabling the smooth operation at high-loading in Li-S system. Using postmortem X-ray photoelectron spectroscopy analysis, this study reveals the presence of strong Lewis acid–base interaction between VO (3d3) and Sx
2– through the coordinate covalent V–S bond formation. Additionally, freestanding nature of the cathodes eradicate the need of additional inactive elements, viz., binders, additional current collectors (Al-foil), and additives. Our results highlight the importance of developing high surface area metal-suboxides/monoxide-based conducting polar host materials for next-generation Li–S batteries.

Figure 1
Surface-Modified Si Nano-Particles as New Anode Materials
Authors: Jiang Sisi , Hu Bin , Neale Nathan , Zhao Bin , Zhang Zhengcheng 
Published: February 2020

Silicon has been considered as one of the most promising anode materials for next generation high-energy lithium-ion battery due to its extremely high theoretical capacity. However, large volume expansion/contraction (~ 300%) during lithiation/delithiation process leads to rapid capacity fade during repeated cycling. The main contributor for the poor performance of Si anode is mainly due to the particle pulverization during the rapid Li+ insertion/extraction and the loss of electrical contact caused by the rearrangement of electrode structure. Nano Si material has shown positive impact on the cell performance. Compared with bulk Si, nanostructured Si (<150 nm) largely resolved the pulverization issue. However, the intrinsic electrolyte reactivity with the lithiated Si particles still exists resulting in the gradual active lithium loss and capacity degradation.
In this presentation, a novel approach attempting to stabilize the surface of the Si particles is reported. Plasma synthesized silicon nanocrystals with Si-H terminal groups were subject to hydrosilylation with various organic compounds containing an allyl group as shown in Figure 1. Preliminary results indicate that the surface functionalization could stabilize the Si/electrolyte interface affording much improved Coulombic efficiency and cycling performance. The latest progress will be presented.

Figure 1
Dry Processed Nickel-Rich Layered Transition Metal Oxide Cathode Electrode
Authors: Shin Joon , Yudi Yudi , Magsino Prince , Wong Wilma , Duong Hieu 
Published: February 2020

Lithium ion battery is a key driver for the proliferation of clean transportation. While its high energy density and operating life time are favorable, the overall cost is limiting widespread adoption. Since the first commercial lithium ion batteries produced by Sony in 1991 for consumer electronics, energy density and life time have gradually improved with the development of new electrode materials such as high capacity LiNixMnyCozO2, LiNi0.8Co0.15Al0.05O2 and silicon, and electrolyte additive such as vinylene carbonate1 and fluoroethylene carbonate2. Recently nickel-rich layered cathode and high capacity silicon anode have been incorporated into commercial lithium ion battery to further increase energy density. While electrode materials have advanced, electrode manufacturing process has largely remained the same, reaching a plateau in coating width, line speed, electrode energy density and production cost. To address these critical needs, Maxwell Technologies has developed a dry battery electrode coating technology with differentiating attributes.
Maxwell’s unique solvent-free coating process used to commercialize ultracapacitors can be adapted to produce electrodes using current state-of-the-art lithium ion battery chemistries and advanced materials3-5 with advantages over conventional wet coating process. The benefits are lower CO2 emission, lower capex and opex cost, improved energy density and the ability to process moisture sensitive or reactive materials. To demonstrate these attributes, we have advanced our dry electrode process development using nickel-rich layered cathode materials to improve energy density, increase cycle life and reduce cell manufacturing cost. We have produced dry electrodes using LiNi0.6Mn0.2Co0.2O2, LiNi0.8Mn0.1Co0.1O2 and LiNi0.8Co0.15Al0.05O2 in roll-to-roll format and characterized their electrochemical performances in small and large capacity pouch cells. Dry process demonstration for prelithiated materials has also been established.
This paper will report the physical properties of nickel-rich layered dry cathode film produced at the lab and pilot production level and their electrochemical performance with coating loading of 30-40mg/cm2 per coating side, which is significantly heavier than a typical wet cast electrode in the range of 20-24mg/cm2 per coating side in commercial high energy 18650 cell.
References:

Aurbach, D.; Gamolsky, K.; Markovsky, B.; Gofer, Y.; Schmidt, M.; Heider, U., Electrochim. Acta, 2002, 47, 1423-1439.

Sinha, N. N.; Burns, J. C.; Dahn, J. R.; J. Electrochem. Soc., 2013, 160, A709-A714.

Duong, H.; Suszko, A.; Feigenbaum, H., 229th ECS meeting, May 29-June 6, 2016, Abstr. #475.

Shin, J.; Duong, H., 233rd ECS meeting, May 13-17, 2018, Abstr. #A03-0365.

Duong, H.; Shin, J.; Yudi, Y., 48th Power Sources Conference, June 11-14, 2018, P34-37.
Influence of Binder Coverage on Interfacial Chemistry of Thin Film LiNi0.6Mn0.2Co0.2O2 Cathodes
Authors: Phillip Nathan Dale , Veith Gabriel M. 
Published: February 2020

Given the pervasive implementation of lithium ion batteries in portable electronics, focus has increased on improving energy density for transportation applications. One route to accomplish this is through the development of high capacity cathodes such as Ni-rich LiNixMnyCo1-x-yO2 (x > 0.5). When charged beyond 4.3 V vs. Li/Li+, however, these materials suffer from irreversible structural changes and gas evolution, accelerating electrolyte decomposition at the cathode/electrolyte interface (CEI). These reactions are convoluted in composite electrodes due to binder and carbon additives as well as porosity creating a poorly defined cathode/electrolyte contact area. To reduce this complexity, thin films comprised solely of active material can be used as a model system to study the interface with controlled quantities and chemistries of coatings such as binders found in standard slurry cast electrodes.
In this study, thin films of LiNi0.6Mn0.2Co0.2O2 were prepared by radio frequency magnetron sputtering to examine the effects of binder coverage morphology and chemistry on the CEI. Binder films were deposited atop the active material by spin coating, which provides a reliable means to cast uniform films down to a few nanometers. Spray coating was used to deposit a conglomerated binder morphology for comparison to the spun coating. These morphologies were repeated for three binders: polyvinylidene difluoride (PVDF), carboxymethyl cellulose (CMC), and lithium polyacrylate (LiPAA) for subsequent characterization. Scanning electron microscopy and atomic force microscopy examined the morphology and topology of the binder films, and samples were weighed with a microbalance to verify equivalent binder loadings across each sample. X-ray photoelectron spectroscopy results indicated that the amount of insulating species present at the interface varied with binder morphology and chemistry. The interfacial species evolved at different rates for each system during cycling, suggesting that binder selection has implications on the initial surface environment as well as over the lifetime of the cathode. These data will be presented alongside Raman, FTIR, and AC impedance spectroscopy to examine how the composition of the interface evolves with cycling and between systems. These results provide valuable insight into the influences of binders on the CEI of Ni-rich cathode materials.

Figure 1
Compact Lithium-Ion Battery Electrodes Fabricated with Lightweight Reduced Graphene Oxide-Based Aerogels
Authors: Pender Joshua Paul , Xiao Han , Dong Ziyue , Cavallaro Kelsey A , Weeks Jason A , Heller Adam , Ellison Christopher J. , Mullins Charles Buddie 
Published: February 2020

We report here the synthesis and fabrication of reduced graphene oxide (rGO)-based aerogels as free-standing lithium-ion battery (LIB) electrodes and 3D scaffolds for supporting conventional LIB active materials (e.g., LiFePO4, Li4Ti5O12, LiNixCoyMnzO2). As a 3D replacement for conventional metal-foil current collectors, we demonstrate the fabrication of compact (2 – 3 g cm-3) electrodes via slurry-infiltrating the porous aerogels with controlled active-material loading (~3 – 30 mg cm-2) and compressing the resultant composites to a desired thickness (~30 – 130 μm from a starting thickness of 3.2 mm). The controlled loading and tunable thickness provide high composite electrode densities that are of essence for consideration in a practical application. Replacement of the usual copper foil (anode) and aluminum foil (cathode) current collectors with the lightweight, integrated rGO-based aerogels drastically reduces the weight and volume occupied by the current collector, thereby increasing the energy density per unit volume and mass at the electrode level.
We further demonstrate that the addition of poly (acrylic acid) (PAA) to the rGO scaffold (referred to as rGO-PAA) provides a versatile platform for exploring a diverse range of structure-function relationships that will guide our understanding of fabricating high-performance electrodes with the lightweight rGO aerogels. For example, due to the electrically-insulating nature of PAA, reducing its content is expected to lead to an increase in electrical conductivity of the aerogel; conversely, we show that the incorporation of PAA facilitates a more uniform pore structure that is expected to improve the ionic conductivity of Li+ ions in the electrolyte. We are exploring this versatility to identify requisite synthesis and processing conditions that optimize the trade-off between electrical conductivity, pore structure, and mechanical properties in the rGO-based aerogels.
Overall, the straightforward synthesis of the rGO-based aerogels starting from inexpensive precursors (graphite and poly (acrylic acid)) provides a scalable fabrication procedure, and the use of commercially-available and high tap-density LIB active materials with the lightweight aerogels enables fabrication of composite electrodes with practical active-material loadings and electrode densities. This approach is unique from that of many other 3D electrodes that use hydrothermal, chemical deposition, or co-precipitation methods to fabricate low tap-density nanomaterials tethered to a 3D substrate that often result in low mass loadings or low volumetric energy densities.
Processing, Fast Formation, and Performance of Aqueous-Processed Low-Co Cathodes for High-Energy Lithium-Ion Pouch Cells
Authors: Wood David L. , Wood Marissa , Mao Chengyu , Li Jianlin , Ruther Rose E. , Du Zhijia 
Published: February 2020

Ni-rich, or low-Co, layered active materials are promising candidates for next-generation cathodes for lithium-ion batteries. However, these materials present processing and performance challenges such as compatibility with water during aqueous electrode formulation, unoptimized SEI/CEI formation conditions during cell assembly, and unstable capacity fade when cycled to upper cutoff voltages above 4.3 V vs. Li/Li+.
The DOE Battery Manufacturing R&D Facility at ORNL (BMF) has recently moved towards low-Co-containing and high-energy LiNi0.8Mn0.1Co0.1O2 (NMC 811) as a new internal cathode baseline and away from LiNi0.5Mn0.3Co0.2O2 NMC 532 for conducting cathode water stability and formation protocol studies. These XRD, Raman spectroscopy, XPS, and TEM studies verified that there was no change in bulk structure of the NMC 811 with long-term water exposure, and only small changes in the surface chemistry. Capacity retention under 0.33C/-0.33C USABC long-term cycling for NMC 811 aqueous-processed single-layer pouch cells was obtained and compared to: 1) the NMP/PVDF processed standard; and 2) NMC 811 exposed to water for 4 hours before processing with the standard NMP/PVDF formulation. The water exposed NMC 811 processed in NMP showed a similar capacity fade to the aqueous processed case. However, all three cases showed excellent capacity retention through 600 cycles, and the aqueous processed cells and NMP processed cells exhibited ~75% and ~80% capacity retention through 1000 cycles, respectively. It was also observed that the differences in capacity fade for all three cases occur within the first ~100 cycles, and the capacity fade slopes were similar from that point on. It is thought that this slight difference in early capacity retention is due to surface chemistry changes of the NMC 811 during aqueous processing and could be remedied with shorter mixing times or a surface protective coating.
To decrease the high manufacturing cost associated with long formation times for low-Co cathodes, five different formation protocols were studied using graphite anodes where the total formation time varied from 10 to 86 h. Electrochemical characterization and post mortem analysis showed that longer formation times do not necessarily improve long-term performance while extremely short formation protocols result in lithium plating and poorer electrochemical performance. It was found that the optimum formation protocol is intermediate in length to minimize impedance growth, improve capacity retention, and avoid lithium plating.
This presentation will focus on recent ORNL advancements in these areas, where aqueous processing conditions (mixing times, water exposure, binder type, etc.) and fast formation protocols are being developed for NMC 811 and that will be extended to other low-Co and Co-free cathodes.
Influence of Calcination Temperature on the Performance of Li and Mn Rich Li1.2Mn0.54Co0.13Ni0.13O2layered Electrode for Lithium Ion Battery
Authors: Piraman Shakkthivel , Alagar Srinivasan 
Published: February 2020

The synthesis/calcination temperature playing a significant role on the performance, safety, and cycle life-time of lithium ion batteries (LiB). In this research work, we have reported the formation of homogeneously dispersed Li1.2Mn0.54Co0.13Ni0.13O2 (LMNCO) with sub-micron spheres architectures with good crystallinity through simple cost-effective precipitation further ball milling synthesis method to enhance the performance of the LIB energy storage system. The synthesized LMNCO cathode electrode materials were calcined at different temperature such as 800, 900 and 1000 °C to examine the influence of calcination temperature on the physiochemical and performance of the electrode. Synthesized LMNCO cathode electrode materials were characterized through TGA/DTA, XRD and SEM studies. The electrochemical characteristics of the synthesized materials were analyzed, the LMNCO prepared at 900 °C was exhibited a best electrochemical performance in LIBs while the charge-discharge profile was carried out in a voltage window of 2.0–4.8 V at 0.1 C rate compared with other materials synthesized at 800 and 1000°C. The first charge/discharge capacity of LMNCO synthesized at 900°C was found to be 259.6 mAh g-1 with the coulombic efficiency of 72.3 %. However, a well capacity retention (95%) of 183.0 mAh g-1 in the 100th cycle was obtained at 1 C rate. Other cathode materials LMNCO-800°C and LMNCO-1000°C were also performed well.
Figure (1) and Figure (2)

References

Leng, F. et al. Eﬀect of Temperature on the Aging rate of Li Ion Battery Operating above Room Temperature. Rep.
5, 12967; doi: 10.1038/srep12967 (2015).

Handel, P. et al. Termal aging of electrolytes used in lithium-ion batteries – An investigation of the impact of protic impurities and diﬀerent housing materials. Power Sources
267, 255–259 (2014)

Feng, L., Cher Ming, T., Rachid, Y. & Minh Duc, L. A practical framework of electrical based online state-of-charge estimation of lithium ion batteries. Power Sources
255, 423–430 (2014).

Keywords: Precipitation;LMNCOsub-microspheres; charge/discharge capacity; LIBs; XRD.

Figure 1
A Highly Hierarchical Hollow Sodium Sulfide Nanospheres Embedded in Spongy Carbon Composite As Cathode for High-Rate Performance Sodium-Sulfur Batteries
Authors: Wang Chuanlong , Wang Huan , Li Weiyang 
Published: February 2020

Sodium-sulfur (Na-S) batteries have shown great promise as the next-generation energy storage systems owing to its high specific energy, low cost and high earth abundance of both Na and S. However, the low electronic conductivity and ionic conductivity of the active materials cause slow kinetics of Na-S chemistry and make high-rate performance impossible. Herein, a facile and scalable approach has been employed to synthesize hollow sodium sulfide (Na2S) nanospheres embedded in a highly hierarchical and spongy conductive carbon matrix, forming an intriguing architecture similar to the morphology of frogspawn coral, which has shown great potential as a cathode for high-rate performance Na-S batteries. The shortened Na-ion diffusion pathway benefited from the hollow structures together with the fast electron transfer from the carbon matrix contributes to high electrochemical reactivity, leading to high capacity and superior cycling performance at various current rates. At current densities of 1.4 and 2.1 A/g, high initial discharge capacities of 980 and 790 mAh/g (based on sulfur) can be achieved, respectively, with reversible capacities stabilized at 600 and 400 mAh/g (based on sulfur) after 100 cycles. As a proof of concept, we demonstrate Na-metal free Na-S batteries paired with Sn embedded in carbon as anode, which shows an exciting cycling performance of an initial capacity of 550 mAh/g (based on sulfur) with a capacity retention over 80% for over 50 cycles. Our work could provide guidance on rational materials design towards the success of room-temperature high-rate Na-S batteries.[1]

Reference:
[1] C.
Wang, H. Wang, X. Hu, E. Matios, J. Luo, Y. Zhang, X. Lu, W. Li, Adv. Energy Mater, 2018, 1803251.

Figure 1