Title: Molecular Engineering of Biorefining Lignin Waste for Solid-State Electrolyte

Abstract

Lignin is the second most abundant renewable biopolymer on Earth but also a waste in both the paper industry and lignocellulosic biorefineries. Recently, lignin valorization has been extensively sought after to return economics, enhance carbon efficiency, and improve the bioeconomy, but the commercial value and size compatibility still hinder its applications. In this study, we developed a facile strategy to apply lignin waste into a solid-state electrolyte (SSE), which represents a safe next generation energy storage. Here, lignin was grafted with polyethylene glycol (PEG), an efficient lithium-ion (Li⁺) conductive polymer, to enable its ion conduction. The synthesized PEG-g-lignin was mixed with poly(vinylidene fluoride)-co-hexafluoropropylene (PVDF-HFP) and PEG-g-lignin-based bis(trifluoromethanesulfonyl)imide (LiTFSI) to prepare a solid polymer electrolyte (SPE), which has an ionic conductivity of 2.5 × 10^–5 S/cm at 25 °C. This result was further enhanced to 6.5 × 10^–5 S/cm by adding an ion-conductive ceramic of Li_6.4La₃Ga_0.2Zr₂O₁₂ (LLGZO), which is referred to as composite polymer electrolyte (CPE). These data represent the highest ones among reported polymer-based SSE. A mechanistic study by using 2D HSQC NMR revealed that PEG-g-lignin has increased ether type β–O–4 linkages that can promote the interchain hopping of Li+ between lignin polymer chains, and ³¹P NMR revealed that themore » lignin phenolic end can be associated by Li⁺. Moreover, the abundant aromatic moieties and methoxyl in PEG-g-lignin also enhanced Li⁺ association and improved its ionic conductivity. The superior ionic conductivity of PEG-g-lignin-based SSE can enable massive applications of this biorefining waste in all-solid-state lithium batteries (ASSLBs), which has potential to promote the energy sector by promoting the bioeconomy and enhancing the renewability and sustainability of future energy storage.« less

Authors:

Li, Qiang  ^[1];

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• Search DOE PAGES for ORCID "0000-0002-4262-6592"

Cao, Daxian ^[1]; Naik, Mandar T. ^[2]; Pu, Yunqiao Joseph  ^[3];

• Search DOE PAGES for author "Pu, Yunqiao Joseph"
• Search DOE PAGES for ORCID "0000-0003-2554-1447"

Sun, Xiao ^[1]; Luan, Pengcheng  ^[1];

• Search DOE PAGES for author "Luan, Pengcheng"
• Search DOE PAGES for ORCID "0000-0001-8896-3263"

Ragauskas, Arthur J.  ^[4];

• Search DOE PAGES for author "Ragauskas, Arthur J."
• Search DOE PAGES for ORCID "0000-0002-3536-554X"

Ji, Tongtai ^[1]; Zhao, Yuyue ^[1]; Chen, Fangqi ^[1]; Zheng, Yi  ^[1];

• Search DOE PAGES for author "Zheng, Yi"
• Search DOE PAGES for ORCID "0000-0003-4963-9684"

Zhu, Hongli  ^[1]

• Search DOE PAGES for author "Zhu, Hongli"
• Search DOE PAGES for ORCID "0000-0003-1733-4333"

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+ Show Author Affiliations

1. Northeastern Univ., Boston, MA (United States)
2. Brown Univ., Providence, RI (United States)
3. Joint Institute for Biological Sciences, Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States)

Publication Date:

Wed Jun 29 00:00:00 EDT 2022

Research Org.:

Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Biological and Environmental Research (BER)

OSTI Identifier:

1878675

Grant/Contract Number:  

AC05-00OR22725

Resource Type:

Accepted Manuscript

Journal Name:

ACS Sustainable Chemistry & Engineering

Additional Journal Information:

Journal Volume: 10; Journal Issue: 27; Journal ID: ISSN 2168-0485

Publisher:

American Chemical Society (ACS)

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; lignin waste; PEG grafting; solid polymer electrolyte; ionic conductivity; waste to energy; sustainability