Title: Nanoscale Protection Layers To Mitigate Degradation in High-Energy Electrochemical Energy Storage Systems

Abstract

In the pursuit of energy storage devices with higher energy and power, new ion storage materials and high-voltage battery chemistries are of paramount importance. Yet, they invite—and often enhance—degradation mechanisms, which are reflected in capacity loss with charge/discharge cycling and sometimes in safety problems. Degradation mechanisms are often driven by fundamentals such as chemical and electrochemical reactions at electrode–electrolyte interfaces, volume expansion and stress associated with ion insertion and extraction, and profound inhomogeneity of electrochemical behavior. Although it is important to identify and understand these mechanisms at some reasonable level, it is even more critical to design strategies to mitigate these degradation pathways and to develop means to implement and validate the strategies. A growing set of research highlights the mitigation benefits achievable by forming thin protection layers (PLs) intentionally created as artificial interphase regions at the electrode–electrolyte interface. These advances highlight a promising—perhaps even generic—pathway for enabling higher-energy and higher-voltage battery configurations. In this Account, we summarize examples of such PLs that serve as mitigation strategies to avoid degradation in lithium metal anodes, conversion-type electrode materials, and alloy-type electrodes. Examples are chosen from a larger body of electrochemical degradation research carried out in Nanostructures for Electrical Energy Storage (NEES),more » our DOE Energy Frontier Research Center. Overall, we argue on the basis of experimental and theoretical evidence that PLs effectively stabilize the electrochemical interfaces to prevent parasitic chemical and electrochemical reactions and mitigate the structural, mechanical, and compositional degradation of the electrode materials at the electrode–electrolyte interfaces. The evidenced improvement in performance metrics is accomplished by (1) establishing a homogeneous interface for ion insertion and extraction, (2) providing mechanical constraints to maintain structural integrity and robust electronic and ionic conduction pathways, and (3) introducing spatial confinements on the electrode material matrix to alter the phase transformation (delaying the occurrence of the conversion reaction) upon Li insertion, which results in superior electrode performance, excellent capacity retention, and improved reversibility. Taken together, these examples portray a valuable role for thin protection layers synthesized over electrode surfaces, both for their benefit to cycle stability and for revealing insights into degradation and mitigation mechanisms. Furthermore, they underscore the impact of complex electrochemical behavior at nanoscale materials and nanostructure interfaces in modulating the behavior of energy storage devices at the mesoscale and macroscale.« less

Authors:

Lin, Chuan-Fu  ^[1];

• Search DOE PAGES for author "Lin, Chuan-Fu"
• Search DOE PAGES for ORCID "0000-0003-4414-8026"

Qi, Yue  ^[2];

• Search DOE PAGES for author "Qi, Yue"
• Search DOE PAGES for ORCID "0000-0001-5331-1193"

Gregorczyk, Keith ^[1]; Lee, Sang Bok ^[1]; Rubloff, Gary W. ^[1]

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+ Show Author Affiliations

1. Univ. of Maryland, College Park, MD (United States)
2. Michigan State Univ., East Lansing, MI (United States)

Publication Date:

Tue Jan 02 00:00:00 EST 2018

Research Org.:

Univ. of Maryland, College Park, MD (United States). Nanostructures for Electrical Energy Storage (NEES) Energy Frontier Research Center (EFRC)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1470065

Grant/Contract Number:  

SC0001160

Resource Type:

Accepted Manuscript

Journal Name:

Accounts of Chemical Research

Additional Journal Information:

Journal Volume: 51; Journal Issue: 1; Related Information: NEES partners with University of Maryland (lead); University of California, Irvine; University of Florida; Los Alamos National Laboratory; Sandia National Laboratories; Yale University; Journal ID: ISSN 0001-4842

Publisher:

American Chemical Society

Country of Publication:

United States

Language:

English

Subject:

25 ENERGY STORAGE; bio-inspired; energy storage (including batteries and capacitors); defects; charge transport; synthesis (novel materials); synthesis (self-assembly); synthesis (scalable processing)