乔羽教授Advanced Functional Materials：构筑晶格匹配的釉质类包覆层以提升高压钴酸锂表界面稳定性

构筑晶格匹配的釉质类包覆层以提升高压钴酸锂表界面稳定性

Figure 1. (a) XRD patterns of LFMP before and after sand milling processing.  The insets are their TEM images respectively. (b) The operating principle of high-speed solid-phase coating machine. (c-e) SEM images of (c) pristine LCO, (d) LCO with homogeneous LFMP nanoparticle layer and (e) continuous LFMP enamel-like layer. The insets correspond to highly magnified SEM images that respectively reveal surface details. (f) FIB-SEM image of LFMP@LCO and elemental distribution of Co, P. (g) HR-TEM image and the corresponding fast Fourier transform (FFT) and inversed FFT (IFFT) of the selected areas at the interface boundary between LCO and LFMP enamel-like layer.

Figure 2. (a) The first charge/discharge profile curves of pristine LFMP, sand-milled LFMP and thermally treated LFMP. The cells were charged to 4.5 V in a CCCV mode (hold 4.5 V for 2 hours) and discharged to 2.5 V at the current density of 50 mA/g. (b) The schematic illustration of Li ions transport path at curvature-matched LFMP/LCO interface formed through sand milling and high-speed coating processing and lattice-matched interface formed via thermal treatment. (c) The GITT curves of LCO and LFMP@LCO and the corresponding Li diffusion coefficients during charging to 4.6 V. (d) The second charge state EIS spectra and the fitting results of LCO and LFMP@LCO. The corresponding equivalent circuit diagrams are displayed in the insets. (e) Fitting results of lattice-matched interface impedance (Rinter) during charging to 4.6V. (f) Leakage current profiles during floating-charge tests (with a floating time of 6 h) for LCO and LFMP@LCO.

Figure 3. (a) XANES spectra of pristine LCO, charged LCO and charged LFMP@LCO. (b-c) Typical galvanostatic charge/discharge profiles curves and the corresponding dQ/dV curves of (b) LCO and (c) LFMP@LCO cathodes at 1 C (1 C=200 mA/g) for 3-4.6 V. (d) Discharge capacity hysteresis against cycle numbers profiles of LCO and LFMP@LCO within 3-4.6 V in half cells under 1 C at room temperature. (e) Discharge capacity hysteresis, (f) energy efficiency, and (g) average voltage against cycle numbers profiles of LCO and LFMP@LCO within 3-4.55 V in half cells under 1 C at 55 oC.

Figure 4. (a-c) DRIFT spectra of the (a) C=O stretching region, the (b) C-O and C-O-C stretching region and the (c) P-F stretching region acquired from pristine LCO, charged LCO and LFMP@LCO surface after long cycling without additional rinsing, allowing the electrolytes to remain. The figures on the right-hand side display simulated spectra of dehydrogenated EC (deH-EC), Li ⁺ -coordinated EC (Li ⁺ -EC), and Li ⁺ -coordinated dehydrogenated EC (Li ⁺ -deH-EC). Simulated spectra of DEC-derived species (deH-DEC, Li ⁺ -DEC, and Li ⁺ -deH-DEC) are also presented. Simulated spectra of PF6- as well as its hydrolysis products (PF ₅ , PF ₃ O) are also displayed. (d) Calculation results of the energy difference obtained by the energy of adsorbing complete EC on the cathode (LCO and LFMP) surface minus the energy of binding dehydrogenated EC to the cathode surface. (e-f) TEM images of cycled LCO and LFMP@LCO surface. The CEI outline is marked with orange dotted lines. (g-h) TOF-SIMS depth profiles (normalized to maximum) of fragments of interest (organic C ₂ HO-/C ₂ H ₃ O ^- and inorganic PO ₂ -/POF ₂ ^- ) obtained on cycled LCO and LFMP@LCO cathodes. The insets show the 3D distribution of dissolved Co species (CoF ₃ ^- ).

Figure 5. (a) The lattice structure between LFMP (110) and LCO (010) planes and the corresponding charge density difference (CDD) maps at the interface. The yellow region represents the increase in charge density. (b) PDOS calculations of O 2p orbitals in bulk LCO and at LFMP (110)/LCO (010) interface. The insets are the corresponding coordination environment of lattice oxygen (including octahedral configuration in LCO bulk and tetrahedral configuration at LCO/LFMP interface). The blue dotted line represents Fermi level. (c) The enthalpy of oxygen release reaction in three different scenarios: pure LCO, LCO coated with LFMP, as a function of lithium content variation. (d) OEMS analysis of the evolution of O ₂ on LCO and LFMP@LCO during charging. The corresponding galvanostatic charge curves are presented in the upper portion of the figure. (e) The k3-weighted Fourier transforms of cobalt K-edge EXAFS spectra measured on charged LCO and LFMP@LCO. The fitted Co-O coordination numbers are presented in the inset, implying that the CoO ₆ plates are better preserved in LFMP@LCO. (f-g) XRD patterns and MS profiles for the O ₂ during heating of delithiated LCO and LFMP@LCO. The results demonstrate that the thermal stability of LFMP-LCO blended cathodes is improved, as its onset temperatures for the structural transformation and the release of O ₂ are postponed.

https://doi.org/10.1002/adma.202308656

厦门大学孙世刚院士/乔羽教授招聘二次电池方向博士后 （正极结构方向）

应聘条件：

1、已取得或即将取得博士学位，年龄在35周岁以下；

2、具有独立开展研究工作的能力，以第一作者身份发表过二次电池能源电化学方向SCI一区论文2篇以上（能力特别突出、或课题组紧缺方向可降低要求）；

3、熟练掌握锂离子电池为主的二次电池体系相关知识，有较强的独立研究工作能力。优先考虑具有正极材料研发（富锂/钠材料、材料结构分析）的申请者；

4、良好的英文阅读与写作能力；并且能够协助指导研究生完成科研工作（另有偿）；

5、优秀的学术道德和团队合作精神。

待遇条件：

1、基本薪酬：年薪32-35 W；

2、提供厦大博士后公寓（翔安校区：约六七十平方米，房租 8-10元/平方米/月）或相应租房补贴；

3、博士后子女按学校教职工子女同等待遇办理入托儿所、幼儿园、入学；（注）入选 “博士后创新人才支持计划项目（博新计划）”、“香江学者计划”者，相关待遇按照国家及厦门大学相关规定执行。详情和具体规定，请登录厦大博士后网站查询：https://postdoctor.xmu.edu.cn/main.htm；

4、成果特别突出的博士后，可协助其申报厦门大学南强拔尖人才计划，入选后可直接聘为正式副教授、特任研究员，具体待遇如下：享受厦门大学教授同等待遇，年薪35万；购房和安家补贴100万元，并可优先享受政府人才购房政策；学校提供100-200万元科研启动经费；每年可配备至少两名硕博士研究生，协助完成科研工作。

申请方式：

欢迎感兴趣的学者加盟，提供以下材料：个人简历，包括学习工作经历、主要研究工作内容、代表论文论著清单、代表作、获得的奖励情况等，发送至以下邮箱，邮件主题请注明“姓名+博士后申请”。

邮箱：yuqiao@xmu.edu.cn

（cc: ）