融合课程思政与创新思维的有机化学教学探索与实践

在化学强基班中进行了课程思政、创新思维和有机化学课程教学深度融合的探索。课堂上精心选择教学案例,利用知识的多重价值,实现知识传授、价值引领与创新能力培养的有机结合。课后组织学生进行文献调研活动,以达到夯实基础、拓宽视野的创新思维训练目的,最终实现教育立德树人的根本任务。

High-modulus solid electrolyte interphase layer with gradient composition enables long-cycle all-solid-state lithium-sulfur batteries

All-solid-state lithium-sulfur batteries(ASSLSBs) have become one of the most potential candidates for the next-generation high-energy systems due to their intrinsic safety and high theoretical energy density.However, PEO-based ASSLSBs face the dilemma of insufficient Coulombic efficiency and long-term stability caused by the coupling problems of dendrite growth of anode and polysulfide shuttle of cathode. In this work, 1,3,5-trioxane(TOX) is used as a functional additive to design a PEO-based composite solidstate electrolyte(denoted as TOX-CSE), which realizes the stable long-term cycle of an ASSLSB. The results show that TOX can in-situ decompose on the anode to form a composite solid electrolyte interphase(SEI) layer with rich-organic component. It yields a high average modulus of 5.0 GPa, greatly improving the mechanical stability of the SEI layer and thus inhibiting the growth of dendrites. Also,the robust SEI layer can act as a barrier to block the side reaction between polysulfides and lithium metal.As a result, a Li-Li symmetric cell assembled with a TOX-CSE exhibits prolonged cycling stability over 2000 h at 0.2 m A cm^(-2). The ASSLSB also shows a stable cycling performance of 500 cycles at 0.5 C.This work reveals the structure–activity relationship between the mechanical property of interface layer and the battery's cycling stability.

工科专业大学化学课程思政教学探索与实践——以华南理工大学为例

思政元素融入专业教学是当前高等教育课程改革的价值导向和必然趋势。本文结合作者多年大学化学课程从教经验以及虚拟教研室建设要求,从教学顶层设计、课程设置优化、实践能力培养和师资德育能力提升四个方面介绍了大学化学课程思政教学的探索与实践,以期为工科类大学培养新时代大国工匠提供新的视角。

课程思政视域下大一新生科学素养构建探索——以“有效数字”教学为例

有效数字知识点在大学阶段以其使用年级多、覆盖专业面广的特点,成为塑造学生科学素养的有效手段与途径。本文在课程思政视域下,结合理论课堂与实验课堂,以真实问题为情境,采用引导式、沉浸式教学模式,由点到面,多措并举,有效解决了有效数字的教学困境,为大一新生科学素养构建奠定基础。

Status and prospect of garnet/polymer solid composite electrolytes for all-solid-state lithium batteries

Solid polymer electrolytes(SPEs), such as polyethylene oxide(PEO), are characteristic of good flexibility and excellent processability, but they suffer from low ionic conductivity and small Li+transference number at ambient temperature. Inorganic solid electrolytes(ISEs), garnet-type Li7La3Zr2O12 and its derivatives(LLZO-based) in particular, possess high ionic conductivity at room temperature, wide electrochemical stability window, large Li+transference number as well as good stability against Li metal anode.Nevertheless, lithium dendrites growth, interfacial contact issue and brittle nature of LLZO-based ceramic electrolytes prevent their practical applications. In response to these shortcomings, LLZO-based/polymer solid composite electrolytes(SCEs), taking complementary advantages of two kinds of electrolytes, and thus simultaneously improving the electrode wettability, ionic conductivity and mechanical strength, have been made to develop high-performance SCEs in recent years. Herein, the intrinsic properties and research progress of LLZO-based/polymer SCEs, including LLZO-based/PEO SCEs(LLZO-based/PEO SCEs with uniform dispersion of LLZO-based fillers and LLZO-based/PEO layered SCEs) and LLZO-based/novel polymers SCEs, are summarized. Besides, comprehensive updates on their applications in solid-state batteries are also presented. Finally, challenges and perspectives of LLZO-based/polymer SCEs for advanced allsolid-state lithium batteries(ASSLBs) are suggested. This review paper aims to provide systematic research progress of LLZO-based/polymer SCEs, to allow for more efficient and target-oriented research on improving LLZO-based/polymer SCEs.

LiF and LiNO_(3) as synergistic additives for PEO-PVDF/LLZTO-based composite electrolyte towards high-voltage lithium batteries with dualinterfaces stability

Solid electrolytes with desirable properties such as high ionic conductivity,wide electrochemical stable window,and suitable mechanical strength,and stable electrode-electrolyte interfaces on both cathode and anode side are essential for high-voltage all-solid-state lithium batteries(ASSLBs)to achieve excellent cycle stability.In this work,a novel strategy of using LiF and LiNO_(3) as synergistic additives to boost the performance of PEO-PVDF/LLZTO-based composite solid electrolytes(CSEs)is developed,which also promotes the assembled high-voltage ASSLBs with dual-interfaces stability characteristic.Specifically,LiF as an inactive additive can increase the electrochemical stability of the CSE under high cut-off voltage,and improve the high-voltage compatibility between cathode and CSE,thus leading to a stable cathode/CSE interface.LiNO_(3) as an active additive can lead to an enhanced ionic conductivity of CSE due to the increased free-mobile Li+and ensure a stable CSE/Li interface by forming stable solid electrolyte interphase(SEI)on Li anode surface.Benefiting from the improved performance of CSE and stable dualinterfaces,the assembled NCM622/9[PEO_(15)-LiTFSI]-PVDF-15 LLZTO-2 LiF-3 LiNO_(3)/Li cell delivers a high rate capacity of 102.1 mAh g^(-1) at 1.0 C and a high capacity retention of 77.4%after 200 cycles at 0.5 C,which are much higher than those of the ASSLB assembled with additive-free CSE,with only 60.0 mAh g^(-1) and 52.0%,respectively.Furthermore,novel cycle test modes of resting for 5 h at different charge states after every 5 cycles are designed to investigate the high-voltage compatibility between cathode and CSE,and the results suggest that LiF additive can actually improve the high-voltage compatibility of cathode and CSE.All the obtained results confirm that the strategy of using synergistic additives in CSE is an effective way to achieve high-voltage ASSLBs with dual-interfaces stability.

Nickel-catalyzed arylcyanation of alkenes via cyano group translocation:access to 1,n-dinitriles or 4-amino nitriles

Herein,a nickel-catalyzed arylcyanation of unactivated alkenes via cyano group translocation with aryl boronic acids has been developed.These transformations provided a robust approach to constructing structurally diverse 1,n-dinitriles or 4-amino nitriles from easily prepared and commercially available starting materials.The cyano group translocation was achieved,involving the addition into the intramolecular C–N triple bond followed by the retro-Thorpe reaction.Mechanistic studies revealed that high temperature and CsHCO_(3) as the base were crucial for the cyano group translocation.

A self-repairing polymer-inorganic composite coating to enable high-performance Zn anodes for zinc-ion batteries

There are some critical issues hindering the practical applications of aqueous zinc-ion batteries(zIBs),although they possess high safety and low cost as one of promising energy storge devices,such as the Zn dendrite growth and the by-product of Zn_(4)SO_(4)(OH)_(6)-xH_(2)O(ZHS)resulted from some side reactions in a mild electrolyte.Herein,a compact and self-repairing solid electrolyte interface(SEl)film,as labeled the PVDF-Zn(TFSI)_(2)-ZHS coating[The PVDF and Zn(TFSI)_(2)are polyvinylidene fluoride and zinc bis(trifluoromethanesulfonyl)imide,respectively],which turns the in-situ generated ZHS into a beneficial ingredient onto the pre-coated PVDF-based composite coating layer containing Zn(TFSI)_(2),was designed and fabricated by a simple doctor blade method.It is shown that the SEl layer can effectively isolate Zn from the electrolyte and homogenize the Zn^(2+)flux,and thus effectively suppress side reactions and dendrites growth.Benefiting from the hybrid SEl layer,a symmetric cell exhibits a high cycling stability over 750h at 2.0 mA/cm^(2)and 2.0 mAh/cm^(2),and meanwhile,a full-cell,coupled with K^(+) pre-intercalationα-MnO_(2)(KMO)cathode,displays excellent rate performance,stable coulombic efficiency and an acceptable cycle life.This work provides a feasible approach for simple and scalable modification of Zn anodes to achieve high performance.

碳基材料修饰聚烯烃隔膜提高锂硫电池性能研究

采用硫单质作正极和金属锂为负极组成的锂硫(Li⁃S)电池具有很高的理论比能量(2600 Wh·kg^(-1)),被认为是一种具有广泛应用前景的二次电池。其中,正极硫具有高的理论比容量(1675 mAh·g^(-1)),储量丰富且环境友好。然而,硫较差的导电性、多硫化物的穿梭效应和锂枝晶生长等导致了Li⁃S电池在循环过程中容量衰减快、库仑效率低和安全隐患等问题,严重阻碍了其大规模应用。通过隔膜修饰提高Li⁃S电池的性能是一种有效的方法,近年来取得了很大进展。碳材料是较常见的一种隔膜修饰材料,本文综述了近年来常见碳材料及碳基复合材料用于修饰Li⁃S电池隔膜进而改善电池性能方面的研究进展,重点介绍了修饰层的设计及提升Li⁃S电池容量的机理。

N,O co-doped porous carbon with rich pseudocapacitive groups exhibiting superior energy density in an acidic 2.4 V Li_(2)SO_(4)electrolyte

Designing a carbon material with a unique composition and surface functional groups for offering high specific capacity in a wide voltage window is of great significance to improve the energy density for the supercapacitor in a cheap and eco-friendly aqueous electrolyte.Herein,we develop an efficient strategy to synthesize a N,O co-doped hierarchically porous carbon(NODPC-1.0)with moderate specific surface area and pore volume as well as rich heteroatoms using a deep eutectic solvent(DES)as an activator.It is found that NODPC-1.0 with a large proportion of pseudocapacitive functional groups(pyrrole-N,pyridineN and carbonyl-quinone)can work stable in an acidic 2 mol/L Li_(2)SO_(4)(pH 2.5)electrolyte,exhibiting specific capacities of 375 and 186 F/g at the current densities of 1.0 and 100 A/g,respectively.Also,the assembled symmetric capacitor using the NODPC-1.0 as the active material and 2 mol/L acidic Li_(2)SO_(4)(pH 2.5)as the electrolyte shows an outstanding energy density of 74.4 Wh/kg at a high power density of 1.44 k W/kg under a broad voltage window(2.4 V).Relevant comparative experiments indicate that H+of the acidic aqueous electrolyte plays a crucial part in enhancement the specific capacity,and the abundant pseudocapacitive functional groups on the surface of the NODPC-1.0 sample play the key role in the improvement of electrochemical cycle stability under a broad voltage window.

The synergistic effect of P-doping and carbon coating for boosting electrochemical performance of TiO_(2) nanospheres for sodium-ion batteries

P-doping is an effective way to modulate the electronic structure and improve the Na+diffusion kinetics of TiO_(2), enabling enhanced electrochemical performance. However, it is a challenge to prepare TiO;with a high P-doping concentration starting from TiO_(2)in a crystalline state. In this work, we design a novel two-step route for constructing a carbon-coated anatase P-doping TiO_(2)nanospheres(denote as(PAn TSS)@NC) with high P-doping concentration, by utilizing amorphous TiO;nanospheres with the ultrahigh specific area as P-doping precursor firstly, and followed by carbon coating treatment. Experimental results demonstrate that P is successfully doped into the crystal lattice and carbon layer is well coated on the surface of TiO_(2), with P-doping and carbon-coating contents of ~13.5 wt% and 10.4 wt%, respectively,which results in the enhanced pseudocapacitive behavior as well as favorable Na+and electron transferring kinetics. The(P-AnTSS)@NC sample shows excellent rate and cycle performance, exhibiting specific capacities of 177 and 115 m Ah/g at 0.1 and 1.0 A/g after 150 and 2000 cycles, respectively.