【物理化学学报】doi: 10.1016/j.actphy.2025.100087
提升钴酸锂(LCO)正极的充电截止电压是提高锂离子电池(LIBs)能量密度的直接策略。然而,高电压下正极-电解质界面相(CEI)的不稳定性严重制约了高能量密度LIBs的发展。因此,本研究利用无碳酸乙烯酯(EC)的电解液设计,通过构建兼具化学稳定性与机械强度的氟/硼复合CEI以提升界面稳定性。采用碳酸丙烯酯(PC)及氟代碳酸乙烯酯(FEC)作为溶剂,增强电解液的抗氧化稳定性,促进CEI中氟化锂(LiF)组分的生成,提升其机械强度。同时,引入双草酸硼酸锂(LiBOB)添加剂,在CEI中形成含硼交联聚合物(LiBxOy)组分,以其柔性结构特征弥补LiF层的不足之处。最终,构建出具有富无机相(LiF和Li2C2O4)嵌入含硼类聚合物(LiBxOy)基体结构的刚柔并济CEI。这种CEI其兼具结构致密性、良好的机械稳定性与电化学稳定性等优点,有效抑制高电压下LCO的界面副反应及不可逆结构退化。实验结果表明,无EC的PC基电解液使LCO正极在4.6 V高截止电压下展现出优异的电化学性能,0.5C倍率循环200次后容量保持率达82%。此外,石墨||LCO全电池在4.5 V截止电压下表现出显著提升的循环稳定性,并实现−40 – 80 ℃宽温域范围内的稳定运行,验证了该优化电解液衍生的刚柔并济CEI的有效性。本研究突破传统EC基电解液设计范式,为开发高性能、宽温域及可持续PC基电解液提供了新思路。
【物理化学学报】doi: 10.3866/PKU.WHXB202305026
电催化二氧化碳(CO2)还原被认为是将CO2转化为可再生能源产品的一种有前途的方法。开发性能优异的电催化剂高效完成这一重要反应是关键。镍基催化剂广泛应用于电催化CO2还原研究,但是,镍纳米颗粒经常表现较差的催化性能。在本文中,通过在氮气气氛中高温热解镍基金属有机骨架(MOF)、尿素和炭黑混合物,获得了镍纳米颗粒负载于多孔碳氮中的催化材料(NiNPs-NC)。有趣的是,NiNPs-NC在H型和流动相电池中都表现出优异的CO2电还原性能。在H型电解池和−0.67 – −1.07 V vs. RHE (可逆氢电极)电位窗口内,NiNPs-NC催化CO2还原为CO的法拉第效率大于90%,其中,在−0.87 V vs. RHE时,CO的法拉第效率约为100%。在流动相电解池和−0.50 – −0.70 V vs. RHE电位窗口内,NiNPs-NC催化CO2还原为CO的选择性大于95%。电化学阻抗谱图和塔菲尔斜率表征显示,NiNPs-NC的高催化活性归因于其在催化过程中的快速电荷转移。本文提供了一种制备高效CO2电还原催化剂的方法。
【无机化学学报】doi: 10.11862/CJIC.20260055
Aiming at the problem of water pollution, a broad-spectrum response composite material CQDs/PW12/CdS modified by carbon quantum dots (CQDs) was prepared via a microwave-assisted hydrothermal method using glucose as the carbon source, cadmium sulfide (CdS) and phosphotungstic acid (PW12) as precursors. The photocatalytic mechanism of CQDs/PW12/CdS is more inclined towards the Z-scheme heterojunction. The optimized CQDs/PW12/CdS heterojunction composites achieved 93.01% photodegradation efficiency of rhodamine B (RhB) at 120 min of simulated sunlight irradiation, and they also exhibited a favorable degrading effect on common dyes and antibiotics in water. Using lactic acid as the sacrificial reagent, the photocatalytic hydrogen production activity of the developed photocatalyst was evaluated under simulated sunlight irradiation. According to the experimental results, after 8 h of irradiation, the CQDs/PW12/CdS composite material showed the highest H2 production rate (12.34 mmol·g-1), which was six times that of the monomer CdS (2.05 mmol·g-1). The enhancement of photocatalytic activity is attributed to the effective separation of photogenerated charges caused by the anisotropic junctions in the CQDs/PW12/CdS system.
