Journal of Inorganic Materials ›› 2024, Vol. 39 ›› Issue (12): 1331-1338.DOI: 10.15541/jim20240206

Special Issue: 【能源环境】储能电池(202412)

• RESEARCH ARTICLE • Previous Articles     Next Articles

Development of Quasi-solid-state Na-ion Battery Based on DPEPA-derived Gel Polymer Electrolyte

KONG Jianfeng1(), HUANG Jiecheng1, LIU Zhaolin2, LIN Cunsheng2(), WANG Zhiyu1,2()   

  1. 1. State Key Lab of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China
    2. Branch of New Material Development, Valiant Co., Ltd., Yantai 265503, China
  • Received:2024-04-22 Revised:2024-05-09 Published:2024-06-24 Online:2024-06-24
  • Contact: WANG Zhiyu, professor. E-mail: zywang@dlut.edu.cn;
    LIN Cunsheng, senior engineer. E-mail: lincunsheng@valiant-cn.com
  • About author:KONG Jianfeng (1999-), male, Master candidate. E-mail: fengfeng1014@mail.dlut.edu.cn
  • Supported by:
    National Key R&D Program of China(2022YFB4101600);National Key R&D Program of China(2022YFB4101605);National Natural Science Foundation of China(52372175);Innovation and Technology Fund of Dalian(2023JJ12GX020);Fundamental Research Funds for the Central Universities(DUT24ZD406)

Abstract:

Compared to Li-ion batteries, Na-ion batteries hold significant advantages and market value for achieving low-cost and large-scale energy storage, thanks to the utilization of cheap and abundant Na resources. However, the use of highly flammable liquid electrolytes with leaky risk raises safety concerns for conventional Na-ion batteries under abuse conditions such as mechanical damage, short-circuiting, and thermal runaway. Limited electrochemical stability of liquid electrolytes also hinders further enhancement of the performance of Na-ion batteries for practical use. This study reports a facile way for the preparation of high-performance gel polymer electrolyte (GPE) by thermal-driven radical in-situ polymerization of dipentaerythritol penta-/hexa-acrylat (DPEPA). This GPE exhibits an ionic conductivity of 1.97 mS·cm-1, a Na+ transference number of 0.66, and a broad electrochemical stability window. The DPEPA displays a lower lowest unoccupied molecular orbit (LUMO) energy level than that of ethylene carbonate (EC) and diethyl carbonate (DEC) solvents, allowing for its preferential decomposition alongside NaPF6 on the anode surface. This leads to a stable organic-inorganic composite film of solid-state electrolyte interphase, inhibiting the decomposition of electrolyte solvents on the anode surface. The quasi-solid-state Na-ion battery employing Na(Ni 1/3Fe1/3Mn 1/3)O2 (NFM) cathode and hard carbon (HC) anode in this GPE exhibits a high capacity retention rate of 92% after 300 stable cycles at a current density of 120 mA·g-1, while achieving the specific capacities of 99-120 mAh·g-1 within a wide temperature range of 20-80 ℃. In-situ X-ray diffractometer analysis reveals the highly reversible structural evolution of the NFM cathode during Na storage and the “adsorption-pore-filling” mechanism of Na+ storage in the HC anode. All data in this research demonstrates that introducing polymers with low LUMO energy levels proves an effective approach to enhance the electrochemical stability of solid-state Na-ion batteries while improving cell safety.

Key words: Na-ion battery, quasi-solid-state battery, gel polymer electrolyte, thermal-driven radical in-situ polymerization, Na storage mechanism

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