bluuebunny/crossref_metadata_2025_split huggingface dataset:
Next-Generation Li-ion Batteries Made with Spatial Atomic Layer Deposition as an Enabling Technology
Authors: Ameen Mahmoud , Beeker Ide , Haverkate Lucas , Anothumakkool Bihag , Grob Frank , Hermes Dorothee , Huijssen Nico , Khandan del Sepideh , Roozeboom Fred , Unnikrishnan Sandeep 
Published: December 2020

Today, Li-ion batteries are key devices in energy storage, with a wide set of applications ranging from mW to kW, such as portable electronics devices, electric vehicles and grid-storage. Typically, high energy density anodes such as Si or Li, combined with Ni- or Li-rich cathodes 1,2 are necessary to obtain the targeted gravimetric energy density (>350 Wh/kg). However, several high-potential redox-chemistries can lead to serious safety and degradation issues during charge-discharge cycling due to oxidative and reductive instabilities 3, that often occur at the electrode-electrolyte interfaces 4. Therefore, for every Li-ion battery chemistry the optimization of these interfaces with chemo-mechanically stable and Li-ion conductive passivation layers is essential in mitigating the non-compatibility of the individual cell components. These interface stabilizing layers can be incorporated either in-situ by using electrolyte additives or ex-situ by chemical and physical methods.
One popular option here is offered by atomic layer deposition (ALD) which is today’s technology of choice to achieve films with superior quality and 3D-conformality with atomic-scale thickness precision. However, conventional vacuum-based temporal ALD is not compatible with industrial high-throughput roll-to-roll battery electrode production. Here, the technique of large-area atmospheric-pressure spatial-ALD (s-ALD) as pioneered by TNO-Holst Centre over a decade ago can offer prime solutions for various applications including thin-film batteries 5. This technique opens up a wide range of cost-effective applications based on materials like metal oxides, nitrides, sulfides, oxysulfides as well as hybrid organic-inorganic material combinations.
In this presentation, we will discuss the growth of several s-ALD films made from Al2O3, TiO2, and ZnO which have been specifically optimized for dendritic Li-growth suppression, interface stabilization, and cathode degradation protection. Next, we will discuss some recent results on the up-scalable s-ALD growth of thin LiPON electrolyte films with a high Li-ion conductivity of >10-7 S/cm, low electronic conductivity of <10-12 S/cm, and high stability against anodic Li-metal during cycling. This electrolyte is also essential in the development of protective layers in liquid and polymer electrolyte-based Li-ion batteries, and in thin-film solid-state batteries with ultra-thin electrolyte layers and planar and 3D topologies.

REFERENCES

S. Myung et al., ACS Energy Lett. 2, 196–223 (2017).

G. Assat and J. M. Tarascon, Nat Energy 3, 373–386 (2018).

H. Ryu et al., Chem. Mater. 3 (30), 1155-1163 (2018).

D. Aurbach et al., Solid State Ionics 148, 405–416 (2002).

P. Poodt et al., J. Vac. Sci. and Technol. A 30, 010802 (2012).
Binder Free Carbon Fiber-Based High-Voltage Cathode for Lithium-Ion Batteries
Authors: Tsai Tsung-Yu , Liu Yi-Hung 
Published: December 2020

Introduction

With increasing demands of large-scale electronic applications such as electric vehicles (EVs) and hybrid electric vehicles (HEVs), lithium ion batteries (LIBs) with high energy density and power density are desired. To meet the performance requirements, an electrode design that enables to accommodate more active material loading while reducing additives, such as binders and conductive agents, is drawing much attention from researchers. Currently, Al foil is commonly used as the current collectors for cathodes of LIBs. However, corrosion of Al foil could become a serious issue, particularly for long-term cycling at high voltage, deteriorating battery performance [1]. On the contrary, carbon fibers (CFs) are thermally and electrochemically stable, and they can work as good electrical conductors with lightweight, thereby becoming a potential candidate for current collector application[2]. In the current study, we aim to combine nickel-manganese-chromium based cathode material and CFs to develop a composite electrode that can tolerate high-voltage operation.

Experimental

First, heat and acid treatments were carried out to remove resin from CFs surface. Then, electrodeposition of the pretreated CFs was performed in a solution containing nickel, manganese, and chromium ions, to obtain precursor fibers. After that, the precursor fibers went through hydrothermal reaction and calcination, forming a CF-based composite. The composite was further grinded, slurried, and ﬁltrated on a carbon paper to complete the composite electrode. The electrodes were characterized through SEM, TEM, XRD, EDS, XPS and their electrochemical performance was evaluated through a coin cell (CR2032) with lithium metal foil as a counter electrode. In addition, 1 M LiPF6 in a mixture of ethylene carbonate : dimethyl carbonate (1:1 in volume ratio) was used as the electrolyte, and a polyolefin film was used as the separator.

Results and Discussion

From the experiment results, it is convinced that the electrode fabrication process is appropriate to prepare the CF-based composite electrodes. However, properties of the electrodes, including morphology, chemical composition, and crystallinity, vary depending on the fabrication conditions. More interestingly, it is found that Cr doping can stabilize the structure of the Li-Ni-Mn-Cr-O active material with increased crystallinity. The Li-Ni-Mn-Cr-O/CF cathode with proper Cr doping content demonstrates favorable electrochemical performance against high-voltage operation (3.0 ~ 4.9 V). It delivers discharge capacities of 143 and 104 mAh g-1 at 0.2 C and 1 C, respectively. In addition, the cathode possesses excellent cycling stability with a capacity retention over 95% after 100 cycles.

References

[1] M. Wang, M. Tang, S. Chen, H. Ci, K. Wang, L. Shi, L. Lin, H. Ren, J. Shan, P. Gao, Z. Liu and H. Peng, Adv. Mater., 29, 1703882 (2017).
[2] Y. H. Liu, H. H. Lin and Y. J. Tai, J. Alloy. Compd., 735, 580–587 (2018).
Conductive Polymers As Hybrid Battery-Capacitor Electrode Materials
Authors: Schoetz Theresa , Messinger Robert J. , Ponce de Leon Carlos , Bund Andreas , Ueda Mikito , Prodromakis Themis 
Published: December 2020

The disruption in next-generation batteries can only be realised by employing both new advanced materials and designs, eventually allowing to holistically achieve new levels of performance, safety and sustainability in a single battery system. To close the gap between high power and energy per unit weight, new materials are needed that can act as a battery and capacitor simultaneously. Conductive polymers, e.g. poly(3,4-ethylenedioxythiophene) (PEDOT), used with ionic liquids or semi-solid ionogels have recently attracted attention as hybrid battery-(pseudo)-capacitor systems, achieving a specific capacity, energy, and power of 40-180 Ah kg-1, 50-230 Wh kg-1, and 30-140 W kg-1 when used as positive electrodes in rechargeable aluminium batteries 1-4. In addition, the polymer composites are non-flammable, non-toxic, economically available and recyclable at low-cost. In comparison to other charge storage materials, like graphite, conductive polymers are less limited by their capacity as the electrode architecture can be redesigned from a conventional 2D design to an interconnected 3D electrode-electrolyte network, allowing a higher active surface, shorter charge transfer and ion diffusion paths for fast charging (up to 80C 4), and controllable electrode shapes/sizes (Figure A 3). The performance of conductive polymers can be tailored by their synthesis path and conditions 1,5. The relationship between electrode fabrication, underlying operating mechanisms, and performance was studied by in operando methods such as electrochemical atomic force microscopy (EC-AFM), and electrochemical microgravimetry (EQCM) 3.
The main achievement is the visualisation of reversible morphological modifications at the nano-scale (Figure B and C 3) of the conductive polymer as a function of state-of-charge. Such changes influence significantly the viscoelastic material properties, which are linked directly to the electrochemical fabrication process 5. Overall, the findings provide an explanation why conductive polymers behave like a hybrid battery-(pseudo)-capacitor (Figure D), setting a new standard for how energy storage can be approached.
[1] Heinze, J. et al. Chemical Reviews
2010, 110, 4724–4771.
[2] Hudak, N.S. The Journal of Physical Chemistry
2014
,
118, 5203–5215.
[3] Schoetz, T. et al. Journal of Materials Chemistry A
2018, 6, 17787–17799.
[4] Schoetz, T. et al. Journal of the Electrochemical Society
2020, 28, 101176.
[5] Schoetz, T. et al. Electrochimica Acta
2018
,
263, 176–183.

Figure 1
(Invited) Lithium Ion Transfer Kinetics of Size Regulated TiO2(B) Nanosheets with Vertical, Random, and Horizontal Alignment for High Rate Lithium Ion Capacitors and Batteries
Authors: Sugimoto Wataru , Nagatani Itsuki , Yoshida Tomohiro , Takimoto Daisuke , Mochizuki Dai , Hideshima Sho 
Published: December 2020

TiO2(B) has a high theoretical capacity of 335 mAh g-1 for Li+ intercalation and thus is a promising candidate as negative electrodes for lithium-ion capacitors and Li-ion batteries. For high rate lithium-ion transfer, it is important to shorten the Li+ diffusion path by using nanostructured TiO2(B). In this work, TiO2(B) nanosheets with different equivalent diameter D
e of 300 nm and 30 nm were prepared. In addition, the orientation of the TiO2(B) nanosheets was manipulated by altering the deposition method and drying process. For large-sized TiO2(B)(300 nm) nanosheet electrodes, the orientation effect was not clear and the amount of lithiation (SOC) was almost the same. Even at a rather low loading of 0.35 mg/cm2, only 1/5 of the theoretical capacity could be intercalated (Li0.2TiO2, 20% SOC) at 0.2C rate. By downsizing TiO2(B) to D
e=30 nm, a two time increase in rate performance (Li0.4TiO2 at 0.2C) was obtained for vertically-aligned electrodes. Although the orientation of small-sized TiO2(B) had a large influence on Li+ transfer kinetics, 100% SOC could not be achieved even at 0.2C, suggesting the lack of electronic conductivity as a governing factor.1

To better understand the Li+ transfer kinetics, the lack of electronic conductivity was circumvented by adopting a vertically aligned reduced graphene oxide (V-rGO) electrode2 as a porous current collector. Three different size TiO2(B) nanosheets (300, 150, and 70 nm) were deposited on V-rGO at a loading of 0.20 mg/cm2. CVs at 0.5 mV/s reveals that 334 and 332 mA/g (100% SOC) is obtained for TiO2(B)/V-rGO with D
e=70 and 150 nm, respectively. On the other hand, for the 300 nm sized TiO2(B)/V-rGO, only 55% SOC was achieved (186 mAh/g). The trend in Li+ transfer kinetics becomes clearer at higher scan rate (10 mV/s) with the capacity scaling with decreasing equivalent diameter; 89, 194, and 233 mAh/g for D
e=300, 150 and 70 nm TiO2(B)/V-rGO. Discussion on results of b-value analysis and Li+ penetration depth will be given in detail in the talk.
This work was partially supported by an Advanced Low Carbon Technology Research Development Program (JST-ALCA, JPMJAL1008).
[1] T. Yoshida, D. Takimoto, D. Mochizuki, W. Sugimoto, Electrochem., in press.
[2] D. Mochizuki, R. Tanaka, S. Makino, Y. Ayato, W. Sugimoto, ACS Appl. Energy Mater.,2(2), 1033 (2019).
Investigation of Cause of Deterioration of Redox Mediator Fixed Electrode for Li-Air Battery
Authors: Miyashiro Kae , Mochizuki Takeshi , Momma Toshiyuki , Matsuoka Koji , Nagatsuka Tomomi 
Published: December 2020

Currently, lithium-ion batteries are widely used as storage devices and further capacity increase of battery is required, while lithium-ion batteries are reaching the theoretical capacity. Lithium-air batteries are expected to be realized in the future, as power storage devices with even higher energy density are required due to the development of IoT and the spread of electric vehicles with a low environmental load. However, many problems remain for the practical application of lithium-air batteries, and it is difficult to obtain sufficient discharge capacity as an insulating discharge product covers the cathode as the reaction progresses, as a problem during discharge. In addition, during charging, a large overvoltage is required for the charging reaction that decomposes lithium peroxide, which is an insulating solid, generated during discharging. Therefore, redox mediators that mediate these charge / discharge reactions are drawing attention. However, when the redox mediator is added to the electrolyte, the redox mediator, which should mediate the cathode reaction, diffuses toward the anode and reacts with lithium, or the redox mediator oxidized at the cathode during charging is reduced at the anode and overcharged by the redox shuttle. It has become a problem. Therefore, in our research, we are fixing the redox mediator on the surface of the cathode in order to prevent it from diffusing into the anode and reacting with lithium metal.
So far, our laboratory has selected TEMPO (2,2,6,6-tetramethylpiperidine 1-oxyl) as a redox mediator and produced a TEMPO immobilized CP (carbon paper) cathode. When this cathode was used, reduction of charging overvoltage and suppression of overvoltage were confirmed, suggesting a redox mediator effect and a redox shuttle forcing effect(Fig.1). However, as a result of carrying out a charge / discharge cycle test using this, it was confirmed that the charge overvoltage increased after repeating charge / discharge cycle(Fig.2).
CV measurements were conducted in Ar atmosphere before and after the charge and discharge processes, as revealed that the redox peaks of TEMPO became smaller after charge and discharge, suggesting decreased amount of reactive TEMPO. Observation of the cathode after charging and discharging with SEM or XPS to investigate the cause of deterioration revealed no clear consideration. The deterioration was considered to be the complicated structure of carbon paper with entangled carbon fibers.

Figure 1
Dependence of Impedance Response of Li-S Battery on Polysulfide Solubility of Electrolyte I - Initial Stage of Discharge
Authors: Hashizume Kota , Momma Toshiyuki , Yokoshima Tokihiko , Togasaki Norihiro , Nakao Aiko , Nara Hiroki , Osaka Tetsuya , Yaji Toyonari 
Published: December 2020

Lithium-sulfur (Li-S) battery has higher theoretical specific capacity than commercial lithium-ion batteries. However, one of serious problems in sulfur cathode to be solved to realize a commercial Li-S battery is polysulfide dissolution, causing lowering charge-discharge capacity and round-trip efficiency. In previous studies, glyme-Li+ solvent ionic liquid (SIL)1) and polypyrrole film containing ionic liquid2) were proposed to mitigate dissolution of polysulfide. Meanwhile, dependence of sulfur cathode’s reaction mechanism on polysulfide solubility of electrolyte is still unclear. In this study, electrochemical impedance spectroscopy (EIS) at various depth of discharge was performed in two types of lithium-sulfur batteries using electrolytes with different polysulfide solubility. This paper describes that polysulfide solubility in electrolyte largely influences the impedance response at initial stage of discharge in Li-S batteries. For cathode and electrolyte, X-ray absorption near edge structure (XANES) was also performed in order to analyze the valence of sulfur species at various depth of discharge.
Figure 1 shows discharge curves of Li-S cells with polysulfide soluble electrolyte (1M LiTFSI in 1,3-dioxolane (DOL)/1,2-dimethoxyethane (DME) 1:1 (v/v)) and with polysulfide insoluble SIL electrolyte (Li(G3)TFSI/hydrofluoroether (HFE) 1:4 (v/v)). Figure 2 (a) and (b) show Nyquist plots obtained by the cells using DOL/DME and SIL, respectively. A remarkable difference was observed in the diameter of semicircles in a frequency range of 1 kHz – 10 Hz; in both cases, semicircle decrease as discharge progression in the same manner, while decrease of the semicircles with DOL/DME was more notable. In addition, another semicircle in a frequency range of 10 Hz - 1 Hz was observed only in the Nyquist plots with SIL electrolyte. These results indicate that the semicircles in higher frequency region (1 kHz – 10 Hz) are attributed to dissolved polysulfide and the semicircle in lower frequency region (10 Hz – 1 Hz) is attributed to undissolved polysulfide. XANES measurement confirms that signal by sulfur (2472 eV) decreased until potential reached 2.1 V with DOL/DME and until 1.5 V with SIL. These results indicate that reduction of sulfur proceeds until 2.1 V with DOL/DME and until 1.5 V with SIL which is in good agreement with the result from impedance response by EIS.

Acknowledgement

This work was partly supported by Advanced Low Carbon Technology Research, Development Program Special Priority Research Area “Next-Generation Rechargeable Battery” (ALCA-Spring) from the Japan Science and Technology Agency (JST) (Grant Number JPMJAL1301).

Reference

(1) Kaoru Dokko et al., Journal of the Electrochemical Society, Volume 160, Issue 8, A1304-A1310 (2013).
(2) Natsuki Nakamura et al., J Power Sources, 274, 1263-1266 (2015).

Figure 1
Dependence of Impedance Response of Li-S Battery on Polysulfide Solubility of Electrolyte II - Mid - End Stage of Discharge
Authors: Yokoshima Tokihiko , Togasaki Norihiro , Nara Hiroki , Nakao Aiko , Osaka Tetsuya , Hashizume Kota , Hirayanagi Tomoe , Momma Toshiyuki , Yaji Toyonari 
Published: December 2020

Sulfur is a promising cathode material for the lithium based battery because of its advantages such as eco-friendness, abundance in nature, and high theoretical capacity of 1675 mAh g-1. However, sulfur cathodes are not without their own intrinsic problems such as low ionic and electronic conductivity, large volumetric expansion upon lithiation from S8 to Li2S, and the dissolution of so-called polysulfide intermediates (Li2Sx where x represents a value between 4 and 8). In previous studies, glyme-Li+ solvent ionic liquid (SIL)1) and polypyrrole film containing ionic liquid2) were proposed to mitigate dissolution of polysulfide. Meanwhile, dependence of sulfur cathode’s reaction mechanism on polysulfide solubility of electrolyte is still unclear. In this study, electrochemical impedance spectroscopy (EIS) at various depth of discharge was performed in two types of lithium-sulfur batteries using electrolytes with different polysulfide solubility. This paper describes that polysulfide solubility in electrolyte largely influences the impedance response at mid - end stage of discharge in Li-S batteries.
Figure 1 shows discharge curves of Li-S cells with polysulfide soluble electrolyte (1M LiTFSI in 1,3-dioxolane (DOL)/1,2-dimethoxyethane (DME) 1:1 (v/v)) and with polysulfide insoluble SIL electrolyte (Li(G3)TFSI/hydrofluoroether (HFE) 1:4 (v/v)). Figure 2 (a) and (b) show Nyquist plots obtained by the cells using DOL/DME and SIL, respectively. A remarkable difference was observed in the diameter of semicircles in lower frequency range of 10Hz – 0.1 Hz at potential of 2.1 - 1.5 V. The semicircle was observed with SIL at 2.1 V, and the diameter of the semicircle increased with discharge progression. No semicircle was observed at 1.9-1.5V. On the other hand, no semicircle with DOL/DME was observed at 2.1 - 1.5 V. However, impedance response at 2.1 V changed to that at 1.9 - 1.5V. The difference at 2.1V was attributed to DOD and/or state of polysulfide in electrolyte. There was no large difference of impedance response with these electrolytes at 1.9 V -1.5 V. It is thought that similar (semi-) solid-state reactions without electrolyte was occurred, because of no effect of solving polysulfide of Li2S2 and Li2S in both electrolytes.
Acknowledgement
This work was partly supported by Advanced Low Carbon Technology Research, Development Program Special Priority Research Area “Next-Generation Rechargeable Battery” (ALCA-Spring) from the Japan Science and Technology Agency (JST) (Grant Number JPMJAL1301).
Reference
(1) K. Dokko et al., J. Electrochem. Soc., 160, A1304-A1310 (2013).
(2) N. Nakamura et al., J Power Sources, 274, 1263-1266 (2015).

Figure 1
(Invited) How Far Can We Push Conventional Silicon Technology and What are the Future Alternatives?
Authors: Saraswat Krishna C. 
Published: December 2020

Si CMOS technology has dominated the microelectronics industry, with continued scaling. However, future scaling is reaching practical and fundamental limits. Currently, strained-Si channel with high-k/metal gate is the dominant technology. Si FinFETs have provided further innovation to improve electrostatic control of the channel and thus reduce leakage. However, performance enhancement of Si CMOS is beginning to saturate with scaling to nanoscale. To go beyond these limits novel materials and structures are being aggressively studied. Higher mobility semiconductors, like Ge, GeSn and III-Vs, together with innovative device structures could increase drive current and reduce power consumption and delay. Carbon nanotubes and graphene offer very high mobility, excellent electrostatic control of the channel but have problems in manufacturability. Graphene also has the problem of ~0 bandgap making it not very useful for logic. Recently 2D materials like metal sulfides, telurides and selenides have emerged as potential candidates for nanoscale devices.
Is Ge PMOS and III-V NMOS co-integration on Si feasible or a headache for the manufacturing folks? Can we have all Ge or all III-V CMOS or it is just a fantasy? Can CNT FETs become manufacturable? Are 2D materials more promising? This talk will try to answer some of these questions.