高温固相法合成锂离子电池正极材料LiNi0.8Co0.2O2研究

研究了高温固相法合成锂离子电池正极材料LiNi0.8Co0.2O2时原材料、气氛、温度、时间、Li:(Ni Co)化学计量比例、氧气流量、二次烧结等参数对制备电极活性材料结构和电性能的影响，使用其优化后的工艺参数，制备出容量为170mAb/g的LiNi0.8Co0.2O2,并对此正极材料组成的电池性能进行了测试。     

A black phosphorus-graphite hybrid as a Li-ion regulator enabling stable lithium deposition

Lithium (Li) metal anodes have been regarded as the most promising candidates for high energy density secondary lithium batteries due to their high specific capacity and low redox potential. However, the issues of Li dendrites caused by nonuniform lithium deposition during battery cycling severely hinder the practical applications of Li metal anodes. Herein, a hybrid of black phosphorus-graphite (BP-G) is introduced to serve as an artificial protective layer for the Li metal anode. The two-dimensional few-layer BP, which is lithophilic, combined with the high electronic conductive graphite can act as a regulator to adjust the migration of Li ions, delivering a uniform and stable lithium deposition. As the growth of lithium dendrites is inhibited, the utilization of Li metal achieves > 98.5% for over 500 cycles in Li||Cu half cells, and the life span is maintained over 2000 h in Li||Li symmetric cells with a low voltage hysteresis of 50 mV. Moreover, the LiFePO₄||Li full cell with a BP-G Li-ion regulator presents significantly better specific capacity and cycling stability than that with the bare Li metal anode. Therefore, the introduction of the BP-G Li-ion regulator is demonstrated to be an effective approach to enable stable lithium deposition for rechargeable Li metal batteries.     

锂离子电池用正极材料Li(Co0.2-XNi0.8MnX)O2的合成制备研究

研究了一种制备新型锂离子电池正极材料的工艺方法．通过采用溶胶凝胶法(sol-gel法合成了新型电池正极材料Li(Co0．2-XNi0．8MnX)O2。并采用XRD方法分析了材料的相变过程、烧结温度、烧结时间对材料相合成的影响及不Mn／Co比掺杂对材料相变的影响；通过SEM照片可见，Li(Co0．2-XNi0．8MnX)O2粉末元素分布均匀、粒径为1～4微米．为今后进行充放电性能的测试工作做准备．     

LiCoO2的化学分解浸取过程

废旧锂离子电池中钴的含量较高．钴具有较强的毒性,且资源稀少．为此,研究了废旧锂离子电池的湿法回收工艺过程,并分析了废旧锂离子电池中钴和锂在硫酸溶液中的漫取过程动力学．采用了解体电池塑料外壳、钢壳、正负极材料、N-甲基吡咯烷酮(NMP)分离铝箔与正极活性材料以及硫酸浸取钴与锂的回收工艺．结果表明,铝片的回收率接近100％,钴和锂的浸取率均超过99．6％,同时分析了漫取过程中的工艺参数对钴和锂的漫取率的影响．     

锂离子电池正极材料锰酸锂制备方法的研究进展

LiMn2O4以其价格低、电位高、环境友好、安全性能高等优点,成为最有希望取代LiCoO2的主流材料之一.LiMn2O4的生产制备方法众多, 文中详细介绍了锰酸锂的晶体结构特点,阐述了锰酸锂的各种制备方法,探讨了采用不同的原料、不同的制备方法对提高锰酸锂性能的差异.从电解液方面、尖晶石锰酸锂晶体结构层面分析了其容量衰减的原因,希望能够为锰酸锂材料的研究者提供借鉴,为其生产提供理论依据.     

磷酸铁锂正极材料的研究现状

磷酸铁锂正极材料具有比容量大、安全性高、性价比高以及循环寿命长等优点,被认为是最具应用前景的锂离子电池正极材料之一。论述了橄榄石型磷酸铁锂的晶体结构特征以及充放电反应机制,综述了近年来采用葡萄糖、活性碳和石墨烯等不同的碳源进行碳包覆, 硫离子、镁离子、镍离子、氟离子、钒离子、钠离子和银离子等不同金属离子和非金属离子进行离子掺杂以及蒸发诱导自组装法、碳热还原法和喷雾干燥法等不同合成方法进行材料纳米化等改性方式对锂离子电池磷酸铁锂正极材料的影响。最后简要分析了目前改性方法仍存在的问题,并对其前景进行了展望。     

复合金属氧化物正极材料 Li(CoxNiyMn1-x-y)O2高功率锂离子动力电池的试制及电化学性能的研究

用化学方法合成用于锂离子动力电池正极的新型高电压高容量复合金属氧化物材料Li(Co_xNi_yMn_1-x-y)O₂试制了具有良好热稳定性的高功率 8 Ah 锂离子动力 电池。在研究了该电池的电化学性能后, 研制了用于混合动力电动车辆的电池系统并进行了车载实验。结果表明该 电池系统在深度放电条件下不仅显现出十分优越的循环性能和一致性, 经过模拟工况测试后的数据还表明单体电池升温最高仅为 5℃, 即电池系统还具有良好的热稳定性, 因此该电池系统是适合用于混合动力电动汽车的。     

LiNi0.85-xCoxMn0.15O2电化学性能的第一性原理研究

采用基于密度泛函理论的第一性原理平面波赝势方法计算了空间群为R-3M,具有层状结构的LiNi0.85-xCoxMn0.15O2的带隙、分波态密度、嵌锂形成能和晶胞体积.计算结果表明LiNi0.65Co0.2Mn0.15O2具有较高的可逆容量,又具有较好的电池性能,为该系列金属氧化物中较为理想的锂离子电池正极材料,与文献的结果相比较,我们发现理论计算结果与实验结果有较好的一致性.本文采用CASTEP中原子混合实现镍钴含量的变化后,分析了LiNi0.85-xCoxMn0.15O2的物理性质及电化学性质.揭示了镍钴含量变化对材料作为锂离子电池正极材料的性能的影响,进而为寻找新的正极三元材料提供理论指导.     

离子迁移动力学的计算材料学研究方法概述及其在锂离子电池材料中的应用

锂离子的迁移及扩散动力学行为是影响锂离子电池倍率性能的最重要的因素之一.计算材料学的发展为模拟锂离子在电池材料中的迁移及扩散提供了各种不同的计算方法,包括蒙特卡罗模拟、分子动力学模拟、绝热轨道方法和弹性能带方法等.讨论了这些方法的特点、适用范围、计算结果的精度和可靠性,并就这些方法在研究锂离子电池材料离子输运行为上的应用实例进行综述.     

锂离子电池正极材料安全性能——热稳定性

锂离子电池由于安全性问题，使大容量电池的应用受到限制，比如用作电动汽车（EV）、混合动力汽车（HEV）的动力电源。以不同正极材料组装成AA型锂离子电池，研究其热稳定性。试验结果表明尖晶石型LiMn2O4作为锂离子电池正极材料，热稳定性最好；新型包埋镍酸锂梯度正极材料有高的比能量和优良的循环性。     

锂离子电池正极材料安全性能——过充性能

锂离子电池由于安全性问题,使大容量电池的应用受到限制,比如用作电动汽车（EV）、混合动力汽车（HEV）的动力电源.以不同正极材料组装成AA型锂离子电池,研究其过充性能.试验结果表明尖晶石型LiMn2O4作为锂离子电池正极材料,耐过充性较好;新型包埋镍酸锂梯度正极材料有很好的耐过充性能.     

Pathway for high-energy density LiMnFePO4 cathodes

Polyanion cathodes are credited for its thermal stability and better safety, no matter in lithium ion batteries or sodium ion batteries. Polyanion oxides with phosphate groups came to the public's attention in 1997, and the representative material is LiFePO₄, which has been widely applied and plays a huge role in the field of powder batteries and energy storage system. However, owing to the low lithiation potentials and storage sites, the energy densities of polyanion cathodes have been restricted, resulting of low-endurance and limited application scenarios. Accordingly, here, we use cheap and environmental friendly raw materials as precursors to synthesis high energy density LiMn_0.6Fe_0.4PO₄@C cathode by a simple spray-drying and high temperature calcination process. The self-designed liquid polyacrylonitrile (LPAN) is added for the intention of nanoparticle coating, conductive network construction and particle granulation. The low-cost and carbon-coated LiMn_0.6Fe_0.4PO₄ cathode exhibits excellent reversible capacity, low electrochemical polarization and excellent rate capacity, which maintains 93.5% capacity retention after cycling 1000 times at 5C. The work introduces a new avenue to fabricate olivine structure cathodes with outstanding electrochemical performance for the high energy density lithium ion batteries.     

MXene and MXene-based materials for lithium-sulfur batteries

Lithium-sulfur (Li–S) batteries are regarded as potential alternatives to lithium-ion batteries due to their extremely high theoretical energy density. Nevertheless, Li–S batteries still suffer from low coulombic efficiency, low sulfur utilization, and poor cycling life, which hinder their further applications. To obtain ideal Li–S cells, intensive work has been dedicated to improve the conductivity of the electrode, inhibiting the shuttle of lithium polysulfides, and promoting the redox of sulfur. Two-dimensional transition metal carbides, nitrides or carbonitrides, also known as MXenes, attracting significant research interest in Li–S batteries due to their high conductivity, abundant active sites, layered structure and adjustable surface chemistry. In this review, we summarize the partial etching methods of MXenes with different surface terminations, the role of MXenes in Li–S batteries and MXene-based composites designed for Li–S batteries based on interfacial chemistry and interlayer structure. In the end, we also propose the perspectives of MXenes for Li–S batteries.     

水系锌-石墨电池的研究新进展

水系锌-石墨电池是一种新型的二次电池,基于水系电解液中的阴、阳离子同时参与电化学反应实现储能,因其具有高能量密度、高功率密度和安全廉价等诸多优势,有望成为替代锂离子电池的下一代储能产品。本文综述了近年来水系锌-石墨电池的发展现状,总结了锌负极、石墨正极存在的问题及现有的解决方案,对水系锌-石墨电池的下一步发展进行了预测。     

Effect of Calcining Temperature on the Structure of Li_4Ti_5O_(12)

1 Introduction Recently there had considerable interest in Li4Ti5O12 as a potential anode for use in Li-ion batteries. Usually, it was used as an anode combined with a high voltage cathode[1-5]. It has many advantages compared to the currently used graphite. For example, it presents virtually unlimited cycle life due to zero strain or volume change when lithium intercalates into and de-intercalates from[6]. Generally, Li4Ti5O12 was prepared by a solid-state reaction from stoichiometric amounts of Li2CO3...     

一种大功率快速离子循环型锂电池结构设计

介绍了快速离子循环型锂电池的特点。分析了锂电池结构,即通过强制循环电解液,进行快速离子交换(强制交换)的一种锂离子蓄电池结构。通过强制循环电解液,所述电池可以获得极高的充电、放电速率,极高的热安全性。     

先进能源储存和转换材料专刊社论

The ever-increasing environmental problems and energy challenges have called urgent demand for utilizing green, ef-ficient, and sustainable energy, thus promoting the develop-ment of new technologies associated with energy storage and conversion systems. Amongst a wealth of energy storage devices, Li/Na/K/Zn/Mg ion batteries, metal-air batteries, and lithium–sulfur/all-solid-state batteries together with su-percapacitors as advanced power sources have attracted con-siderable interest due to their conspicuous merits of high en-ergy density, long cycle life, and good rate capability. In the energy conversion systems, solar cells and fuel cells can be considered as mainstream renewable energy resources once their manufacturing cost has decreased to an affordable level. However, the developments of advanced power sources de-pend critically on advances in materials innovation. There-fore, to promote the practical applications of these promising systems, developing high-performance electrode materials has been taken into the center stage in current research areas from chemistry, physics, and materials science fields.     

Li3N film modified separator with homogenization effect of lithium ions for stable lithium metal battery

Lithium metal anode with high theoretical capacity is considered to be one of the most potential anode materials of the next generation. However, the growth of lithium dendrite seriously affects the application of lithium metal anode and the development of lithium metal batteries (LMBs). Herein, an ultrathin Li₃N film modified separator to homogenize the lithium ions and protect the lithium metal anode was reported. Due to the intrinsic properties of Li₃N, the functional separator possessed good thermal stability, mechanical properties and electrolyte wettability, and the homogenization of the lithium ion was realized without increasing the interface impedance. With this functional separator, the Li/Li symmetrical cell could achieve a long cycle with low overpotential for 1000 ​h at a current density of 1 ​mA ​cm⁻². Furthermore, when the full battery was assembled with LiFePO₄ and the discharge capacity could be maintained at 151 mAh g⁻¹ after 400 cycles at 1 ​C. In addition, the full battery also showed good rate performance, and provided a high discharge capacity of 114 mAh g⁻¹ at 5 ​C.     

LiSiPON固态薄膜电解质的结构和性能分析

以Li3PO4和Si3N4为靶材,利用离子束辅助沉积N离子流轰击法制备非晶结构的固态电解质LiSiPON薄膜.实验中,通过控制N2气和Ar气的流量比,调节薄膜的含氮量.利用X线衍射、X线能量色散谱仪和X线光电子能谱仪研究薄膜的结构和组织成分的变化,并通过电化学阻抗测试仪获得薄膜的离子电导率,研究不同氮氩比对LiSiPON薄膜结构、组成和电学性质的影响.结果表明:N2和Ar流量比为1∶1时,薄膜含氮量最高,离子电导率达到最大值,在室温时电解质薄膜的离子电导可达6.8×10-6S/cm,是一种有潜力应用于全固态薄膜锂离子电池的电解质材料.     

硅钨杂多酸锂作为聚并苯/锂二次电池的新型电解质研究

用聚并苯作正极活性材料,金属锂作负极,以硅钨杂多酸锂Li4SiW12O40代替高氯酸锂作电解质,制成了聚并苯/锂（PAS/Li）二次电池,对该二次电池的性能及影响因素尤其是Li4SiW12O40对电池容量、循环性能和自放电性质进行了系统研究.结果表明:与高氯酸理作电解质的PAS/Li二次电池相比,采用该新型电解质的二次电池不仅克服了高氯酸钾易吸水、易爆炸的不利因素,而且还具有较大的比容量和较小的自放电,循环性也很好,是一种新型、优秀的PAS/Li二次电池的电解质.