德国DENIOS科普：锂离子电池的工作原理

为了能够评估锂储能设备带来的危险，了解它们的工作原理非常有帮助。重要知识：不存在“单一”锂电池这样的东西。相反，有大量不同的能量存储系统，其中锂以纯或结合锂形式使用。一次（不可充电）和二次（可充电）锂离子电池之间存在基本区别。一般来说，当我们谈到锂离子电池或锂离子蓄电池时，通常指的是后者。本文将详细介绍锂电池的功能和化学特性。

In order to be able to assess the dangers posed by lithium energy storage devices, knowledge of how they work can be very helpful. Important to know: There is no such thing as “one” lithium battery. Instead, there is a large number of different energy storage systems in which lithium is used in pure or bound form. A basic distinction is made between primary (non-rechargeable) and secondary (rechargeable) lithium-ion cells. In common parlance, the latter are usually meant when we speak of lithium-ion batteries or, better, lithium-ion accumulators. In this article you will learn more about the functionality and chemical properties of a lithium battery.

功能性FUNCTIONALITY

电池组由多个电池组成，具体取决于功率。每个锂离子电池由正极和负极（即阳极和阴极）组成。正负极之间是离子传导电解质。这保证了充电或放电过程中锂离子在电极之间的传输。最著名的锂能源存储设备是使用液体电解质的锂离子电池。

A battery pack is composed of several cells depending on the power. Each lithium-ion cell consists of a positive and a negative electrode, the anode and the cathode. Between them is an ion-conducting electrolyte. This guarantees the transport of lithium ions between the electrodes during the charging or discharging process. The best known form of lithium energy storage devices are the lithium-ion batteries, in which a liquid electrolyte is used.

另一个重要部件是分离器。它防止阳极和阴极之间的直接接触，从而防止短路。放电时，负极侧释放出锂离子和电子。电子流过外部电路并做电功。同时，锂离子通过电解液迁移并通过分离器到达阴极。

Another important component is the separator. It prevents the direct contact between anode and cathode and thus prevents a short circuit. When discharging, lithium ions and electrons are released on the anode side. The electrons flow through the external circuit and do the electrical work. At the same time, the lithium ions migrate through the electrolyte fluid and through the separator to the cathode.

充电时，此过程则相反。根据系统的不同，所使用的结构和材料可能会根据锂离子电池的不同而有所不同。在锂聚合物蓄电池中，电解液与聚合物薄膜的分子结构结合在一起，这样就可以省去单独的分离器。锂聚合物储能只能提供低放电电流

When charging, this process is reversed. Depending on the system, the structure and materials used may vary depending on the lithium-ion battery. In the lithium-polymer accumulator, the electrolyte is incorporated into the molecular framework of a polymer film. This makes it possible to dispense with the separate separator. Lithium-polymer energy storage can deliver only low discharge currents.

然而，聚合物薄膜允许采用扁平设计，这也是为什么这种储能器在手机和笔记本电脑中得到广泛应用的原因。薄膜锂电池是一种用离子导电气体代替电解质的储能装置。这样就可以使用锂金属，从而实现极高的能量密度。该技术是目前锂储能研究的重要组成部分。

However, the polymer film allows a flat design, which is why such energy storage find especially in mobile phones and laptops use. The thin-film lithium cell is an energy storage in which the electrolyte is replaced by an ion-conductive gas. This allows the use of lithium metal and thus an extremely high energy density. This technique is currently an important part of lithium energy storage research.

化学性质CHEMICAL PROPERTIES

德国联邦职业安全与健康研究所 (BAuA) 将锂离子电池视为 REACH 法规下的产品，而美国职业安全与健康管理局 (OSHA) 将电池归类为混合物。在实践中，许多公司即使没有法律义务，也会准备并提供锂电池的安全数据表。这些通常提供有关电池存储和处理的有价值的信息。然而，通常也可以找到化学成分的详细信息，其中提供了有关危险的信息。锂电池基本上可分为阳极、电解液和阴极。

While the German Federal Institute for Occupational Safety and Health (BAuA) regards lithium-ion batteries as products under the REACH regulation, the American Occupational Safety and Health Administration (OSHA) classifies batteries as mixtures. In practice, many companies prepare and make available safety data sheets for lithium batteries even without a legal obligation to do so. These usually provide valuable information on battery storage and handling. However, details of chemical composition can often also be found, which provide information on the hazard. Basically a lithium battery can be divided into the anode, electrolyte fluid and cathode.

通常，石墨 (C) 用作阳极材料，根据 CLP 法规无需进行标签。

As a rule, graphite (C) is used as the anode material, which does not have to be labelled under the CLP Regulation.

许多不同的材料用于阴极。正极材料的确切成分极大地决定了诸如寿命、充电时间和性能等特性。阴极通常使用铁、锰、钴或镍。

Many different materials are used for the cathode. The exact composition of the cathode material significantly determines properties such as lifetime, charging times and performance. Iron, manganese, cobalt or nickel are often used in the cathode.

电解液由有机溶剂和导电盐组成。虽然有多种可能的溶剂，但六氟磷酸锂 (LiPF6) 几乎专门用作导电盐。

The electrolyte fluid consists of an organic solvent and a conducting salt. While there is a large variety of possible solvents, lithium hexafluorophosphate (LiPF6) is almost exclusively used as the conducting salt.

电解液=有机溶剂+导电盐（LIPF6）

ELECTROLYTE LIQUID = ORGANIC SOLVENT + CONDUCTIVE SALT (LIPF6)

各种溶剂混合物的确切化学成分通常是制造商的秘密。但是，通过查看各种数据表，您可以了解所使用的成分。溶剂成分的闪点范围从+160°C到有时低于0°C。这就是锂电池热不稳定性的原因。

The exact chemical composition of the respective solvent mixture is usually a manufacturer's secret. By viewing various data sheets, however, you can get an overview of the components used. The flash points of the solvent components range from + 160 ° C to sometimes below 0 ° C. This explains the thermal instability of a lithium battery.

导电盐除其他成分还含有氟(F) 。释放的非浓缩氢氟酸 (HF) 可能会导致损坏的锂电池出现各种危险情况。

The conductive salt contains fluorine (F), among other things. The released hydrofluoric acid (HF) in non-concentrated form can lead to various hazardous situations in a damaged lithium battery.