The Electronic Conductivity of Single Crystalline Ga‐Stabilized Cubic Li
            7
            La
            3
            Zr
            2
            O
            12
            : A Technologically Relevant Parameter for All‐Solid‐State Batteries

Abstract Replacement of Li-ion liquid-state electrolytes by solid-state counterparts in a Li-ion battery (LIB) is a major research objective as well as an urgent priority for the industry, as it enables the use of a Li metal anode and provides new opportunities to realize safe, non-flammable, and temperature-resilient batteries. Among the plethora of solid-state electrolytes (SSEs) investigated, garnet-type Li-ion electrolytes based on cubic Li7La3Zr2O12 (LLZO) are considered the most appealing candidates for the development of future solid-state batteries because of their low electronic conductivity of ca. 10−8 S cm−1 (RT) and a wide electrochemical operation window of 0 ‒ 6 V vs. Li+/Li. However, high LLZO density (5.1 g cm-3) and its lower level of Li-ion conductivity (up to 1 mS cm−1 at RT) compared to liquid electrolytes (1.28 g cm-3; ca. 10 mS cm−1 at RT) still raise the question as to the feasibility of using solely LLZO as an electrolyte for achieving competitive energy and power densities. In this work, we analyzed the energy densities of Li-garnet all-solid-state batteries based solely on LLZO SSE by modeling their Ragone plots using LiCoO2 as the model cathode material. This assessment allowed us to identify values of the LLZO thickness, cathode areal capacity, and LLZO content in the solid-state cathode required to match the energy density of conventional lithium-ion batteries (ca. 180 Wh kg-1 and 497 Wh L-1) at the power densities of 200 W kg-1 and 600 W L-1, corresponding to ca. 1h of battery discharge time (1C). We then discuss key challenges in the practical deployment of LLZO SSE in the fabrication of Li-garnet all-solid-state batteries.

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Development of Solid Electrolytes for All-Solid-State Batteries

NIPPON GOMU KYOKAISHI ◽

10.2324/gomu.92.430 ◽

2019 ◽

Vol 92 (11) ◽

pp. 430-434

Author(s):

Akitoshi HAYASHI ◽

Atsushi SAKUDA ◽

Masahiro TATSUMISAGO

Keyword(s):

Solid State ◽

Solid Electrolytes ◽

Solid State Batteries ◽

All Solid State Batteries

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Rational Design of Quasi Zero-Strain NCM Cathode Materials for Minimizing Volume Change Effects in All-Solid-State Batteries

10.26434/chemrxiv.10000751.v1 ◽

2019 ◽

Author(s):

Florian Strauss ◽

Lea de Biasi ◽

A-Young Kim ◽

Jonas Hertle ◽

Simon Schweidler ◽

...

Keyword(s):

Solid State ◽

Solid Electrolyte ◽

Cathode Materials ◽

Rational Design ◽

Electrode Materials ◽

Cycling Performance ◽

Mechanical Degradation ◽

Volume Changes ◽

Solid State Batteries ◽

All Solid State Batteries

Measures to improve the cycling performance and stability of bulk-type all-solid-state batteries (SSBs) are currently being developed with the goal of substituting conventional Li-ion battery (LIB) technology. As known from liquid electrolyte based LIBs, layered oxide cathode materials undergo volume changes upon (de)lithiation, causing mechanical degradation due to particle fracture, among others. Unlike solid electrolytes, liquid electrolytes are somewhat capable of accommodating morphological changes. In SSBs, the rigidity of the materials used typically leads to adverse contact loss at the interfaces of cathode material and solid electrolyte during cycling. Hence, designing zero- or low-strain electrode materials for application in next-generation SSBs is desirable. In the present work, we report on novel Co-rich NCMs, NCM361 (60% Co) and NCM271 (70% Co), showing minor volume changes up to 4.5 V vs Li<sup>+</sup>/Li, as determined by <i>operando</i> X-ray diffraction and pressure measurements of LIB pouch and pelletized SSB cells, respectively. Both cathode materials exhibit good cycling performance when incorporated into SSB cells using argyrodite Li<sub>6</sub>PS<sub>5</sub>Cl solid electrolyte, albeit their morphology and secondary particle size have not yet been optimized.

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Rational Design of Quasi Zero-Strain NCM Cathode Materials for Minimizing Volume Change Effects in All-Solid-State Batteries

10.26434/chemrxiv.10000751 ◽

2019 ◽

Author(s):

Florian Strauss ◽

Lea de Biasi ◽

A-Young Kim ◽

Jonas Hertle ◽

Simon Schweidler ◽

...

Keyword(s):

Solid State ◽

Solid Electrolyte ◽

Cathode Materials ◽

Rational Design ◽

Electrode Materials ◽

Cycling Performance ◽

Mechanical Degradation ◽

Volume Changes ◽

Solid State Batteries ◽

All Solid State Batteries

Measures to improve the cycling performance and stability of bulk-type all-solid-state batteries (SSBs) are currently being developed with the goal of substituting conventional Li-ion battery (LIB) technology. As known from liquid electrolyte based LIBs, layered oxide cathode materials undergo volume changes upon (de)lithiation, causing mechanical degradation due to particle fracture, among others. Unlike solid electrolytes, liquid electrolytes are somewhat capable of accommodating morphological changes. In SSBs, the rigidity of the materials used typically leads to adverse contact loss at the interfaces of cathode material and solid electrolyte during cycling. Hence, designing zero- or low-strain electrode materials for application in next-generation SSBs is desirable. In the present work, we report on novel Co-rich NCMs, NCM361 (60% Co) and NCM271 (70% Co), showing minor volume changes up to 4.5 V vs Li<sup>+</sup>/Li, as determined by <i>operando</i> X-ray diffraction and pressure measurements of LIB pouch and pelletized SSB cells, respectively. Both cathode materials exhibit good cycling performance when incorporated into SSB cells using argyrodite Li<sub>6</sub>PS<sub>5</sub>Cl solid electrolyte, albeit their morphology and secondary particle size have not yet been optimized.

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Operando Visualization of Morphological Dynamics in All-Solid-State Batteries

10.26434/chemrxiv.8299406 ◽

2019 ◽

Author(s):

Xiaohan Wu ◽

Juliette Billaud ◽

Iwan Jerjen ◽

Federica Marone ◽

Yuya Ishihara ◽

...

Keyword(s):

Solid State ◽

Solid Electrolytes ◽

Rational Design ◽

Morphological Evolution ◽

Active Material ◽

Composite Layer ◽

Transference Number ◽

Thermal Stabilities ◽

Solid State Batteries ◽

All Solid State Batteries

<div> <div> <div> <p>All-solid-state batteries are considered as attractive options for next-generation energy storage owing to the favourable properties (unit transference number and thermal stabilities) of solid electrolytes. However, there are also serious concerns about mechanical deformation of solid electrolytes leading to the degradation of the battery performance. Therefore, understanding the mechanism underlying the electro-mechanical properties in SSBs are essentially important. Here, we show three-dimensional and time-resolved measurements of an all-solid-state cell using synchrotron radiation x-ray tomographic microscopy. We could clearly observe the gradient of the electrochemical reaction and the morphological evolution in the composite layer. Volume expansion/compression of the active material (Sn) was strongly oriented along the thickness of the electrode. While this results in significant deformation (cracking) in the solid electrolyte region, we also find organized cracking patterns depending on the particle size and their arrangements. This study based on operando visualization therefore opens the door towards rational design of particles and electrode morphology for all-solid-state batteries. </p> </div> </div> </div>

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