Do you really understand electrolytes?

What is electrolyte?

The main materials of lithium-ion batteries are: positive electrode, negative electrode, electrolyte, and separator . As one of the four key materials of lithium-ion batteries, electrolyte is called the "blood" of lithium-ion batteries.

From the working principle of lithium ions, lithium-ion batteries are secondary batteries (rechargeable batteries) that mainly rely on the movement of lithium ions between the positive and negative electrodes to work. During the charging and discharging process, Li+ is embedded and de-embedded between the two electrodes: when charging, Li+ is de-embedded from the positive electrode and embedded in the negative electrode through the electrolyte, and the negative electrode is in a lithium-rich state; the opposite is true during discharge.

Lithium battery-material-electrolyte related

 1. Composition of electrolyte

The basic functions of electrolyte:

It transfers lithium ions between the positive and negative electrodes, but insulates electrons to ensure that the battery can be charged and discharged smoothly.

Ideal electrolyte requirements:

1) It is an excellent conductor for lithium ions and an insulator for electrons;

2) Except for the migration of lithium ions, no other side reactions occur on the electrode surface;

3) Do not react with other battery components;

4) Good chemical stability; safe and environmentally friendly;

Lithium battery industry terms and explanations

 Lithium-ion battery: A battery that uses materials that can undergo lithium ion embedding/de-embedding reactions as positive and negative active materials, and uses organic electrolytes or polymer electrolytes containing lithium salts. It is a secondary battery (i.e., a rechargeable battery) that mainly relies on the movement of lithium ions between the positive and negative electrodes to work.

The role of lithium battery electrolyte

This article introduces the role of lithium battery electrolyte in detail. The electrolyte not only plays a key role in conducting ions to complete the charging and discharging process in the battery, but also has important significance in maintaining the stable performance of the battery, preventing plate corrosion, dissipating heat, controlling temperature, improving energy and power density, providing high voltage and high specific energy, protecting battery safety, and adapting to wide temperature applications. By understanding the role of the electrolyte, it provides a reference for better design and optimization of lithium batteries and improving their performance and safety.

Some common concepts and indicators of lithium batteries

1. Why choose lithium battery?

At present, most power batteries are still lithium batteries. Of course, sodium-ion batteries are gradually beginning to be mass-produced, but they are not the main players yet.

Battery Cell Introduction

1.Classification of battery cells

1.1.Introduction to energy storage

Nickel battery: Nickel-metal hydride battery is a good performance battery. The positive active material of nickel-metal hydride battery is Ni(OH)2 (called NiO electrode), the negative active material is metal hydride, also called hydrogen storage alloy (the electrode is called hydrogen storage electrode), and the electrolyte is 6mol/L potassium hydroxide solution. The advantages of nickel battery are: high energy density, fast charge and discharge speed, light weight, long life, no environmental pollution; the disadvantages are slight memory effect, more management problems, and easy formation of monomer battery separator melting.

Battery cell production process

 1. Production process of battery cells

The production process of cylindrical batteries: front process, middle process and back process.

Pre-process : Process the positive and negative electrode materials and current collectors into a certain coating weight and size

The positive and negative electrodes

Middle process : Wind the pole piece and diaphragm made in the previous process into a winding core and then put it into the shell.

The electrolyte is injected and sealed to form a complete battery structure.

Post-process : An important battery process for the first charging, discharging and activation of cylindrical batteries