Double-Layer Electrolyte Boosts Cycling Stability of All-Solid-State Li Metal Batteries

Changlong Lei; Jingyi Li; Zhouliang Tan; Yue Li; PeiPei He; Yuming Liu; Yunjiao Li; Feixiang Wu; Yi Cheng; Zhenjiang He

doi:10.1021/acsami.3c06118

Double-Layer Electrolyte Boosts Cycling Stability of All-Solid-State Li Metal Batteries

ACS Appl Mater Interfaces. 2023 Jul 5;15(26):31572-31583. doi: 10.1021/acsami.3c06118. Epub 2023 Jun 21.

Authors

Changlong Lei^{1

2

3}, Jingyi Li^{1

2

3}, Zhouliang Tan^{1

2

3}, Yue Li^{1

2

3}, PeiPei He^{1

2

3}, Yuming Liu^{1

2

3}, Yunjiao Li^{1

2

3}, Feixiang Wu^{1

2

3}, Yi Cheng^{1

2

3}, Zhenjiang He^{1

2

3}

Affiliations

¹ School of Metallurgy and Environment, Central South University, Changsha, Hunan 410083, China.
² National Engineering Research Center of Low-carbon Nonferrous Metallurgy, Central South University, Changsha, Hunan 410083, China.
³ Engineering Research Center of the Ministry of Education for Advanced Battery Materials, Central South University, Changsha, Hunan 410083, China.

PMID: 37341215
DOI: 10.1021/acsami.3c06118

Abstract

All-solid-state lithium metal batteries (ASSLMBs), as a candidate for advanced energy storage devices, invite an abundance of interest due to the merits of high specific energy density and eminent safety. Nevertheless, issues of overwhelming lithium dendrite growth and poor interfacial contact still limit the practical application of ASSLMBs. Herein, we designed and fabricated a double-layer composite solid electrolyte (CSE), namely, PVDF-LiTFSI-Li_1.3Al_0.3Ti_1.7(PO₄)₃/PVDF-LiTFSI-h-BN (denoted as PLLB), for ASSLMBs. The reduction-tolerant PVDF-LiTFSI-h-BN (denoted as PLB) layer of the CSE tightly contacts with the Li metal anode to avoid the reduction of LATP by the electrode and participates in the formation of a stable SEI film using Li₃N. Meanwhile, the oxidation-resistance and ion-conductive PVDF-LiTFSI- LATP (denoted as PLA) layer facing the cathode can reduce the interfacial impedance by facilitating ionic migration. With the synergistic effect of PLA and PLB, the Li/Li symmetric cells with sandwich-type electrolytes (PLB/PLA/PLB) can operate for 1500 h with ultralong cycling stability at 0.1 mA cm^-2. Additionally, the LiFePO₄/Li cell with PLLB maintains satisfactory capacity retention of 88.2% after 250 cycles. This novel double-layer electrolyte offers an effective approach to achieving fully commercialized ASSLMBs.

Keywords: Li1.3Al0.3Ti1.7(PO4)3; all-solid-state lithium metal batteries; double-layer electrolyte; lithium metal; poly(vinylidene fluoride).