新型硅-硫锂电池研究进展

高比能量、高安全性是未来储能系统的重要发展方向,在电子产品、航天设备、高续航电动汽车等诸多领域均有迫切需求。硅具有很高的理论比容量,电压平台接近金属锂,采用硅替代锂金属作为负极可以得到新型硅-硫锂电池。本文阐述了新型硅-硫锂电池的特征及存在的关键问题,介绍了全电池中锂源的引入方式,综述了新型硅-硫锂电池正、负极的制备技术及研究进展,总结了不同制备方法存在的优缺点,并详述了目前液态电解质的常见组成、研究进展以及存在的问题。最后结合硅-硫锂电池的发展趋势提出未来重点研究的几个方向,如优化电极/电解质界面、开发固态电解质等。     

Insights into Electrolytic Pre-Lithiation: A Thorough Analysis Using Silicon Thin Film Anodes

Pre-lithiation via electrolysis, herein defined as electrolytic pre-lithiation, using cost-efficient electrolytes based on lithium chloride (LiCl), is successfully demonstrated as a proof-of-concept for enabling lithium-ion battery full-cells with high silicon content negative electrodes. An electrolyte for pre-lithiation based on γ-butyrolactone and LiCl is optimized using boron-containing additives (lithium bis(oxalato)borate, lithium difluoro(oxalate)borate) and CO₂ with respect to the formation of a protective solid electrolyte interphase (SEI) on silicon thin films as model electrodes. Reversible lithiation in Si||Li metal cells is demonstrated with Coulombic efficiencies (C_Eff) of 95–96% for optimized electrolytes comparable to 1 m LiPF₆/EC:EMC 3:7. Formation of an effective SEI is shown by cyclic voltammetry and X-ray photoelectron spectroscopy (XPS). electrolytic pre-lithiation experiments show that notable amounts of the gaseous product Cl₂ dissolve in the electrolyte leading to a self-discharge Cl₂/Cl⁻ shuttle mechanism between the electrodes lowering pre-lithiation efficiency and causing current collector corrosion. However, no significant degradation of the Si active material and the SEI due to contact with elemental chlorine is found by SEM, impedance, and XPS. In NCM111||Si full-cells, the capacity retention in the 100th cycle can be significantly increased from 54% to 78% by electrolytic pre-lithiation, compared to reference cells without pre-lithiation of Si.     

硅基负极材料预锂化技术研究进展

从物理预锂、化学反应预锂和电化学预锂等方面,综述硅基负极材料预锂化技术的研究进展.物理预锂包括:与金属锂粉末直接混合法,将气态的金属锂沉积在硅基负极材料或集流体上的真空热蒸发法,将金属锂负载在集流体上的电化学沉积法;化学反应预锂包括:溶液预锂法,将硅制成硅化锂的高能球磨法,将预锂化前驱体生成稳定LixSiyOz结构的高...     

Research progress of carbon-based lithium ion capacitor

新能源体系的建设和电子设备的飞速发展对储能器件提出了更高的要求,即要求其同时兼具较高的能量密度和功率密度。锂离子电容器（LIC）是一种基于锂离子电池（LIB）和超级电容器（EDLC）双重储能机制的储能器件,兼具超级电容器良好的功率特性和锂离子电池较高的能量密度,有望应用于混合动力汽车、轨道交通、智能电网、能源工程等领域。从锂离子电容器未来的产业化角度出发,炭材料因为资源丰富、制备简单和廉价易得是锂离子电容器的首选材料。本文综述了活性炭等正极炭材料、石墨等负极炭材料、电解液以及锂离子电容器工艺方面的研究进展,并对锂离子电容器未来的发展方向和发展前景作出了展望。     

Silicon-Based Lithium Ion Battery Systems: State-of-the-Art from Half and Full Cell Viewpoint

Lithium-ion batteries (LIBs) have been occupying the dominant position in energy storage devices. Over the past 30 years, silicon (Si)-based materials are the most promising alternatives for graphite as LIB anodes due to their high theoretical capacities and low operating voltages. Nevertheless, their extensive volume changes in battery operation causes the structural collapse of Si-based electrodes, as well as severe side reactions. In this review, the preparation methods and structure optimizations of Si-based materials are highlighted, as well as their applications in half and full cells. Meanwhile, the developments of promising electrolytes, binders and separators that match Si-based electrodes in half and full cells have made great progress. Pre-lithiation technology has been introduced to compensate for irreversible Li⁺ consumption during battery operation, thereby improving the energy densities and lifetime of Si-based full cells. More importantly, almost all related mechanisms of Si-based electrodes in half and full cells are summarized in detail. It is expected to provide a comprehensive insight on how to develop high-performance Si-based full cells. The work can help us understand what happens during the lithiation process, the primary causes of Si-based half and full cells failure, and strategies to overcome these challenges.     

大容量锂离子电容器用锂化硬炭负极

采用硬炭与锂源自放电这种简单的预锂化方法可使锂嵌入硬炭,而后以预锂化硬炭和活性炭分别为负极和正极组装了锂离子电容器,研究了负极预锂化时间对锂离子电容器比容量的影响,结果表明随着预锂化时间的延长,比容量先增大后减小,15 h为最适宜预锂化时间.经过15 h预锂化的锂离子电容器具有最高的能量密度(97.2 Wh·kg^-1)和功率密度(5 412 W·kg^-1)、最小的阻抗和良好的循环性能(1 A·g^-1的电流密度下循环1 000次后,能量保持率为91.2%).三电极数据表明锂离子电容器优异的电化学性能源于正负极材料各自处于合适的工作电压区间.     

Effect of the pre-lithiation capacity of mesocarbon microbeads anode on the performances of a flexible packaging lithium ion capacitors#br#

以活性炭作为正极,预嵌锂的中间相炭微球为负极,制成软包装锂离子电容器。在正负极活性材料质量比为1∶1的条件下,采用恒压嵌锂法对负极进行预嵌锂,嵌锂容量分别为100 mA•h/g、200 mA•h/g、300 mA•h/g。在2～4 V的电压区间内,对软包装器件进行倍率测试及高倍率下的寿命测试。测试结果显示,锂离子电容器单体电容量为4～5 F,预嵌锂容量为200 mA•h/g时电容器展现出最佳的电化学性能,首次充放电能量密度为83.7 W•h/kg（基于正负极活性质量）,在倍率为120 C时,功率密度达8835.4 W/kg,能量密度保持在40.3 W•h/kg。在20 C的倍率下进行充放电寿命测试,500次循环之后,能量密度保持91.6%,1000次循环之后,能量密度保持86.5%。     

Research progress on pre-lithiation in carbon-based lithium-ion capacitor

锂离子电容器属于非对称型超级电容器,通常由电池型负极和电容型正极共同置于有机锂盐溶液中组装而成,兼具超级电容器的高功率特性和锂离子电池的高能量密度,在智能电网、轨道交通、新能源汽车等多个领域具有广阔的应用前景。炭材料由于来源广泛、价格低廉、性能稳定,是锂离子电容器的首选电极材料。因此,炭基锂离子电容器具有竞争性的产业化前景。负极预嵌锂技术对于炭基锂离子电容器的电化学性能具有决定性影响。本文从锂源引入位置的角度,系统回顾了锂离子电容器负极预嵌锂技术的进展情况,并就负极预嵌锂过程中的关键控制因素做了梳理,有助于全面了解负极预嵌锂技术的研究现状,为锂离子电容器的进一步发展提供科学参考。     

硅基负极材料预锂化技术全球专利分析

针对全球及中国硅基负极材料预锂化技术专利申请趋势、申请人和专利技术构成等情况进行分析，从专利角度探讨硅基负极材料预锂化技术发展现状及重点技术路线。目前硅基负极材料预锂化技术正处于快速发展阶段，技术路线尚未统一，以热掺杂和有机锂为代表的化学预锂技术发展迅速，最有可能率先实现产业化应用；中国是硅基负极材料预锂化技术的主要目标市场国，但国内企业相比外国来华企业技术基础薄弱、专利积累少，建议加大研发力度、加强相关专利布局。     

有机介质体系锂离子电容器

锂离子电容器（lithium ion capacitor，LIC）是一种新型的电化学储能器件，可以填补锂离子电池和超级电容器两者之间的性能空白，是下一代高能量密度超级电容器的前进方向。本文首先介绍了锂离子电容器的储能原理分为电解液消耗机制、锂离子交换机制以及混合机制，并围绕高能量密度的有机介质体系锂离子电容器，着重阐述了各类电容及电池型正负极材料的性质特点、优化方向及其研究现状，指出不同材料的优缺点及改性方法。同时叙述了与产业应用相关的预嵌锂技术、隔膜、电解液以及体系匹配等方面的研究现状，总结归纳了这些部件的研究对于比能量、功率、安全、稳定性等性能的提升。在产业化应用方面，针对锂离子电容器不同于锂离子电池和传统超级电容器的性能指标，总结其在智能物流、起重机电源、机器人电源及轨道交通等方面独特的应用前景。最后展望了电极材料微观结构优化及功能集成、电解液专用化，预嵌锂成本进一步压缩、以及检测及原位表征方法的开发等锂离子电容器未来的发展方向。