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Electrolyte stability determines scaling limits for solid-state 3D Li ion batteries

Nano Letters

Ruzmetov, Dmitry; Oleshko, Vladimir P.; Haney, Paul M.; Lezec, Henri J.; Karki, Khim; Baloch, Kamal H.; Agrawal, Amit K.; Davydov, Albert V.; Krylyuk, Sergiy; Liu, Yang; Huang, Jian Y.; Tanase, Mihaela; Cumings, John; Talin, A.A.

Rechargeable, all-solid-state Li ion batteries (LIBs) with high specific capacity and small footprint are highly desirable to power an emerging class of miniature, autonomous microsystems that operate without a hardwire for power or communications. A variety of three-dimensional (3D) LIB architectures that maximize areal energy density has been proposed to address this need. The success of all of these designs depends on an ultrathin, conformal electrolyte layer to electrically isolate the anode and cathode while allowing Li ions to pass through. However, we find that a substantial reduction in the electrolyte thickness, into the nanometer regime, can lead to rapid self-discharge of the battery even when the electrolyte layer is conformal and pinhole free. We demonstrate this by fabricating individual, solid-state nanowire core-multishell LIBs (NWLIBs) and cycling these inside a transmission electron microscope. For nanobatteries with the thinnest electrolyte, ≈110 nm, we observe rapid self-discharge, along with void formation at the electrode/electrolyte interface, indicating electrical and chemical breakdown. With electrolyte thickness increased to 180 nm, the self-discharge rate is reduced substantially, and the NWLIBs maintain a potential above 2 V for over 2 h. Analysis of the nanobatteries' electrical characteristics reveals space-charge limited electronic conduction, which effectively shorts the anode and cathode electrodes directly through the electrolyte. Our study illustrates that, at these nanoscale dimensions, the increased electric field can lead to large electronic current in the electrolyte, effectively shorting the battery. The scaling of this phenomenon provides useful guidelines for the future design of 3D LIBs. © 2011 American Chemical Society.

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TYPE Journal Article YEAR 2012
ScopusOSTI

In situ atomic-scale imaging of electrochemical lithiation in silicon

Nature Nanotechnology

Liu, Xiaohua L.; Wang, Jiang W.; Huang, Jian Y.; Fan, Feifei; Huang, Jian Y.; Liu, Yang; Krylyuk, Sergiy; Yoo, Jinkyoung; Dayeh, Shadi A.; Davydov, Albert V.; Mao, Scott X.; Picraux, S.T.; Zhang, Sulin; Li, Ju; Zhu, Ting; Huang, Jian Y.

In lithium-ion batteries, the electrochemical reaction between the electrodes and lithium is a critical process that controls the capacity, cyclability and reliability of the battery. Despite intensive study, the atomistic mechanism of the electrochemical reactions occurring in these solid-state electrodes remains unclear. Here, we show that in situ transmission electron microscopy can be used to study the dynamic lithiation process of single-crystal silicon with atomic resolution. We observe a sharp interface (∼1 μnm thick) between the crystalline silicon and an amorphous Li x Si alloy. The lithiation kinetics are controlled by the migration of the interface, which occurs through a ledge mechanism involving the lateral movement of ledges on the close-packed {111} atomic planes. Such ledge flow processes produce the amorphous Li x Si alloy through layer-by-layer peeling of the {111} atomic facets, resulting in the orientation-dependent mobility of the interfaces. © 2012 Macmillan Publishers Limited. All rights reserved.

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TYPE Journal Article YEAR 2012
ScopusOSTIDOI

Real-time studies of battery electrochemical reactions inside a transmission electron microscope

Sullivan, John P.; Huang, Jian Y.; Leung, Kevin L.; Fan, Hongyou F.; Liu, Xiaohua L.; Hudak, Nicholas H.

We report the development of new experimental capabilities and ab initio modeling for real-time studies of Li-ion battery electrochemical reactions. We developed three capabilities for in-situ transmission electron microscopy (TEM) studies: a capability that uses a nanomanipulator inside the TEM to assemble electrochemical cells with ionic liquid or solid state electrolytes, a capability that uses on-chip assembly of battery components on to TEM-compatible multi-electrode arrays, and a capability that uses a TEM-compatible sealed electrochemical cell that we developed for performing in-situ TEM using volatile battery electrolytes. These capabilities were used to understand lithiation mechanisms in nanoscale battery materials, including SnO{sub 2}, Si, Ge, Al, ZnO, and MnO{sub 2}. The modeling approaches used ab initio molecular dynamics to understand early stages of ethylene carbonate reduction on lithiated-graphite and lithium surfaces and constrained density functional theory to understand ethylene carbonate reduction on passivated electrode surfaces.

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TYPE SAND Report YEAR 2012
OSTIDOI

Confined cooperative self-assembly and synthesis of optically and electrically active nanostructures : final LDRD report

Coker, Eric N.; Huang, Jian Y.; Rodriguez, Marko A.

In this project, we developed a confined cooperative self-assembly process to synthesize one-dimensional (1D) j-aggregates including nanowires and nanorods with controlled diameters and aspect ratios. The facile and versatile aqueous solution process assimilates photo-active macrocyclic building blocks inside surfactant micelles, forming stable single-crystalline high surface area nanoporous frameworks with well-defined external morphology defined by the building block packing. Characterizations using TEM, SEM, XRD, N{sub 2} and NO sorption isotherms, TGA, UV-vis spectroscopy, and fluorescence imaging and spectroscopy indicate that the j-aggregate nanostructures are monodisperse and may further assemble into hierarchical arrays with multi-modal functional pores. The nanostructures exhibit enhanced and collective optical properties over the individual chromophores. This project was a small footprint research effort which, nonetheless, produced significant progress towards both the stated goal as well as unanticipated research directions.

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TYPE SAND Report YEAR 2011
OSTIDOI

Anisotropic Swelling and Fracture of Silicon Nanowires during Lithiation

Nano Letters

Sullivan, John P.; Liu, Xiaohua L.; Huang, Jian Y.

We report direct observation of an unexpected anisotropic swelling of Si nanowires during lithiation against either a solid electrolyte with a lithium counter-electrode or a liquid electrolyte with a LiCoO2 counter-electrode. Such anisotropic expansion is attributed to the interfacial processes of accommodating large volumetric strains at the lithiation reaction front that depend sensitively on the crystallographic orientation. This anisotropic swelling results in lithiated Si nanowires with a remarkable dumbbell-shaped cross section, which develops due to plastic flow and an ensuing necking instability that is induced by the tensile hoop stress buildup in the lithiated shell. The plasticity-driven morphological instabilities often lead to fracture in lithiated nanowires, now captured in video. These results provide important insight into the battery degradation mechanisms.

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TYPE Journal Article YEAR 2011
OSTIDOI

Fabrication of a nanostructure thermal property measurement platform

Nanotechnology

Harris, C.T.; Martinez, Julio M.; Shaner, Eric A.; Huang, Jian Y.; Swartzentruber, Brian S.; Sullivan, J.P.; Chen, G.

Measurements of the electrical and thermal transport properties of one-dimensional nanostructures (e.g.nanotubes and nanowires) are typically obtained without detailed knowledge of the specimen's atomic-scale structure or defects. To address this deficiency, we have developed a microfabricated, chip-based characterization platform that enables both transmission electron microscopy (TEM) of the atomic structure and defects as well as measurement of the thermal transport properties of individual nanostructures. The platform features a suspended heater line that physically contacts the center of a suspended nanostructure/nanowire that was placed using insitu scanning electron microscope nanomanipulators. Suspension of the nanostructure across a through-hole enables TEM characterization of the atomic and defect structure (dislocations, stacking faults, etc) of the test sample. This paper explains, in detail, the processing steps involved in creating this thermal property measurement platform. As a model study, we report the use of this platform to measure the thermal conductivity and defect structure of a GaN nanowire. © 2011 IOP Publishing Ltd.

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TYPE Journal Article YEAR 2011
ScopusOSTI
Results 1–50 of 95
Results 1–50 of 95