Wang Chengzhi, Jin Haibo, Zhao Yongjie
Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Cluster Science, Ministry of Education of China, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, China.
Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, 100081, China.
Small. 2021 Jun;17(23):e2100974. doi: 10.1002/smll.202100974. Epub 2021 Apr 28.
Inorganic Na Zr Si PO is prospective with a high ionic conductivity but suffers large interfacial resistance and stability issues against sodium metal, hindering its practical application in all-solid-state sodium batteries. A surface potential regulation strategy is adopted to address these issues. Na Zr Si PO (NZSP) ceramic with homogeneously-sintered surface is synthesized by a simple two-step sintering method to promote its uniform surface potential, which is favorable for mitigating the potential fluctuations at the interface against Na metal and enhancing interfacial compatibility. The Na/NZSP interface can be stabilized for over 4 months with a low interfacial resistance of 129 Ω cm at 25 °C. The symmetrical Na/NZSP/Na cell exhibits ultra-stable sodium platting/stripping cycling for over 1000 cycles under 0.1 mA cm . Superior interfacial performance is well retained even under 0.2 mA cm at room temperature. The robust interface is further signified by its excellence under higher current densities of up to 0.85 mA cm at 60 °C. A 4 V all-solid-state Na V Cr (PO ) /NZSP/Na metal battery is demonstrated at ambient conditions, which exhibits superior rate capability and delivers a high reversible capacity of 103 mA h g under 100 mA g for over 400 cycles with a Coulombic efficiency of over 99%.
无机NaZrSiPO具有较高的离子电导率，具有应用前景，但存在较大的界面电阻以及与金属钠的稳定性问题，这阻碍了其在全固态钠电池中的实际应用。采用表面电位调控策略来解决这些问题。通过简单的两步烧结法合成了表面均匀烧结的NaZrSiPO（NZSP）陶瓷，以促进其表面电位均匀，这有利于减轻与金属钠界面处的电位波动并增强界面相容性。在25℃下，Na/NZSP界面能够稳定超过4个月，界面电阻低至129Ω·cm²。对称的Na/NZSP/Na电池在0.1mA/cm²下表现出超过1000次循环的超稳定钠电镀/剥离循环。即使在室温下0.2mA/cm²的电流密度下，也能很好地保持优异的界面性能。在60℃高达0.85mA/cm²的更高电流密度下，其卓越性能进一步证明了该稳定界面的优势。在环境条件下展示了一款4V全固态NaVCr(PO₄)₃/NZSP/Na金属电池，该电池表现出优异的倍率性能，在100mA/g下循环超过400次，库仑效率超过99%，可逆容量高达103mAh/g。
