第一作者：刘洪

通讯作者：范丽珍*

单位：北京科技大学

硫化物固态电解质（SSE）被认为是全固态锂电池最有希望的候选者之一，因为它们具有高离子传导性和出色的延展性。然而，空气稳定性差以及与金属锂的不相容性严重阻碍了它们在全固态金属锂电池中的应用。

基于此，北京科技大学范丽珍教授课题组，在国际知名期刊CEJ上发表的题为“Versatility of Sb-doping enabling argyrodite electrolyte with superior moisture stability and Li metal compatibility towards practical all-solid-state Li metal batteries”的研究论文。

该研究通过多功能的Sb掺杂策略，用于构建具有优异空气稳定性及锂金属相容的硫银锗矿电解质。通过优化掺杂剂浓度，合成的Li₆P_0.925Sb_0.075S₅Cl在室温下具有3.6 × 10^-3 S cm^-1的超高离子电导率。得益于掺杂会在电解质内部形成对水热力学稳定的SbS₄^3-四面体，该电解质即使暴露于空气或者水中，也显示出了优异的结构稳定性和耐水解性。

Sb掺杂后的Li₆P_0.925Sb_0.075S₅Cl可以诱导Li/SSE界面形成Li-Sb合金，从而调节Li⁺的电镀/剥离行为，降低Li⁺在阳极界面的扩散能垒，从而使Li对称电池具有良好的长循环稳定性(稳定循环在0.1 mA cm^-2超过800 h)和显著提高临界电流密度(1.2 mA cm^-2)。最后，无论是暴露前还是暴露后的Li₆P_0.925Sb_0.075S₅Cl电解质都能使全电池具有优异的电化学性能。

采用高能球磨法制备了一系列掺杂Sb的Li₆P_1-xSb_xS₅Cl(0≤x≤12.5%)电解质，通过XRD，拉曼，精修等系统表征了电解质的晶相结构，发现Sb掺杂在晶格中占据4b位点，会与S成键形成SbS₄^3-四面体。

Fig. 1. a) Schematic illustration of the synthesis process for Li₆P_1-xSb_xS₅Cll. b) XRD patterns of the prepared Li₆P_1-xSb_xS₅Cl (0 ≤ x ≤ 12.5%). c) Magnified XRD patterns for the prepared Li₆P_1-xSb_xS₅Cl SSEs in the range of 44° ≤ 2θ ≤ 54°. d) Raman spectra of Li₆P_0.925Sb_0.075S₅Cl SSEs compared with Li₆PS5Cl and Li3SbS4 SSEs. e) Rietveld refinements patterns for the Li₆P_0.925Sb_0.075S₅Cl SSEs. f) Crystal structure of the optimized Li₆P_0.925Sb_0.075S₅Cl SSEs.

要点二:Sb掺杂的Li₆P_0.925Sb_0.075S₅Cl电解质具有优异的电化学性能

通过优化掺杂剂的浓度，所制备Li₆P_0.925Sb_0.075S₅Cl展现出了3.6 × 10^-3 S cm^-1的超高离子电导率。

Fig. 2. a) Nyquist curves at 25 oC and b) Arrhenius plots of the Li₆P_1-xSb_xS₅Cl (0 ≤ x ≤ 12.5%) SSEs tested from 25 to 90 oC. c) Variation of activation energy of electrolytes with Sb doping content. d) Current-time curves of SS/Li6PS5Cl/SS and SS/Li₆P_0.925Sb_0.075S₅Cl/SS symmetric cells under DC polarization.

要点三:Sb掺杂的Li₆P_0.925Sb_0.075S₅Cl电解质具有优异的空气稳定性

得益于在形成了对水热力学稳定的SbS₄^3-基团，Sb掺杂的Li₆P_0.925Sb_0.075S₅Cl具有卓越的空气稳定性，在暴露于潮湿空气中有效的抑制电解质结构退化，离子电导率下降及H₂S气体的产生。

Fig. 3. a) Optical photographs of Li6PS5Cl and Li₆P_0.925Sb_0.075S₅Cl completely immersed in deionized water at room temperature. b) The quantity of H2S gas generated from Li6PS5Cl and Li₆P_0.925Sb_0.075S₅Cl upon exposure to humid air. c) XRD patterns and d) Raman spectra of Li₆PS5Cl and Li₆P_0.925Sb_0.075S₅Cl before and after exposure to humid air. Arrhenius plots of the prepared e) Li₆PS5Cl and f) Li₆P_0.925Sb_0.075S₅Cl before and after exposure to humid air. g) Schematic diagram of the difficulty degree of PS₄ and SbS₄ units when reacted with H₂O according to the DFT calculations.

要点四:Sb掺杂的Li₆P_0.925Sb_0.075S₅Cl电解质具有优异的锂金属相容性

Sb掺杂的Li₆P_0.925Sb_0.075S₅Cl电解质能够在负极界面原位形成Li-Sb合金，可以有效的降低Li⁺扩散能垒和调控Li⁺在界面处的沉积/剥离行为，从而显著提升与金属锂的界面相容性及对锂枝晶的抑制能力。因此，所组装的Li/Li₆P_0.925Sb_0.075S₅Cl/Li对称电池中显示出高的临界电流密度（1.2 mA cm^-2）及在优异的锂对称循环稳定性（0.1 mA cm^-2稳定循环超过800 h）。

Fig. 4. Galvanostatic Li plating/stripping profiles in the a) Li/Li₆PS5Cl/Li and b) Li/Li₆P_0.925Sb_0.075S₅Cl/Li symmetric cells at step-increased current densities at room temperature. Polarization curves of the c) Li/Li₆PS₅Cl/Li and d) Li/Li₆P_0.925Sb_0.075S₅Cl/Li symmetric cells at 0.1 mA cm^-2 and 0.1 mAh cm^-2. e) Li 1s XPS spectra of the interfacial composition concerning the original Li₆P_0.925Sb_0.075S₅Cl after cycling between Li and Li₆P_0.925Sb_0.075S₅Cl. f) Kinetic energy barriers to Li⁺ diffusion on Li and Li-Sb alloy based on the DFT calculations. g) Schematic representation of enhanced dendrite inhibition capability and good lithium metal compatibility at the Li₆P_0.925Sb_0.075S₅Cl-derived Li anode interface.

要点五:基于电解质组装电池，验证了Sb掺杂策略的多功能性

无论是原始合成的Li₆P_0.925Sb_0.075S₅Cl还是空气暴露的Li₆P_0.925Sb_0.075S₅Cl都能使全固态锂电池在室温下具有优异的电化学性能。

Fig. 5. a) Schematic diagram illustrating the configuration of the fabricated LNO@NCM/Li₆P_0.925Sb_0.075S₅Cl/Li ASSLMBs. b) Cycling capability and c) charging/discharging curves of LNO@NCM/Li₆P_0.925Sb_0.075S₅Cl/Li batteries at 0.2C. d) Impedance spectra of the LNO@NCM/Li₆P_0.925Sb_0.075S₅Cl/Li batteries before and after 60 cycles. e) Rate performance of the LNO@NCM/Li₆P_0.925Sb_0.075S₅Cl/Li batteries f) The initial charging/discharging curves of the LNO@NCM/Li₆P_0.925Sb_0.075S₅Cl/Li ASSLMBs using Li₆P_0.925Sb_0.075S₅Cl as the SSE before and after air exposure.

Versatility of Sb-doping enabling argyrodite electrolyte with superior moisture stability and Li metal compatibility towards practical all-solid-state Li metal batteries

范丽珍教授，北京科技大学教授，国家万人计划、科技部中青年科技创新领军人才、科睿唯安高被引科学家。2004年获得清华大学博士学位，师从南策文院士。2003年8月起先后多次在日本东京索尼公司、日本九州大学、德国马普固态研究所（合作教授Joachim Maier）及美国德州大学奥斯汀分校（合作教授John B Goodenough）做访问研究、博士后研究、洪堡基金研究员和访问学者。长期从事固态电池关键材料的研究，在包括Nat. Rev. Mater.、Joule、Adv. Mater.、Adv. Energy Mater. 等期刊发表学术论文200余篇，授权专利23项，省部级奖励1项。