On June 25, Ningde Times chairman Zeng Yuqun revealed at the Chongqing Auto Show that in addition to all-solid-state batteries and semi-solid-state batteries, including condensed-matter batteries that everyone has never heard of, Ningde Times is working on it. Zeng Yuqun said that the innovation of the power battery chemical system, the innovation of the structure, the innovation of the manufacturing, and the innovation of the business model can be integrated to promote the development of the new energy vehicle industry.
There is not much news about the condensed matter battery of the Ningde era. This article analyzes the condensed matter battery technology with personal understanding. To distinguish from the state of matter, matter can be divided into gaseous, liquid, solid, plasma, gel and so on.
The so-called condensed state battery should refer to the gel state battery. The gel state means that the colloidal particles or macromolecules in the sol or solution are connected to each other under certain conditions to form a spatial network structure. The compound forms a complex with the metal cation in the metal salt, and such a special dispersion system is called a gel. The inside of the gel often contains liquid, the viscosity is very large, and the fluidity is lost, and the whole system becomes an elastic semi-solid with a uniform appearance and a certain shape.
The basic snit of the battery core is generally composed of the following areas: (1) current collector; (2) negative electrode; (3) separator; (4) positive electrode; (5) electrolyte, which is filled in the pores of the positive and negative electrodes and the separator . Different types of batteries (mainly taking lithium batteries as an example) can be divided into the following types from the physical composition of positive and negative electrodes, separators and electrolytes:
conventional lithium-ion battery
The positive and negative electrodes are solid porous electrodes composed of active particles, conductive agents and binders, and the pores are filled with liquid electrolyte;
The separator is also composed of a solid porous polymer membrane and a liquid electrolyte filled in the pores, which only conducts lithium ions and isolates electrons.
Gel polymer separator battery
The positive and negative electrodes are solid porous electrodes, and the pores are filled with liquid electrolyte;
The separator is a gel electrolyte. The polymer polymers are interconnected to form a three-dimensional network structure. The pores are filled with an electrolyte that cannot flow to form a gel electrolyte, which conducts lithium ions and isolates electrons.
Gel Electrode Battery
Both positive and negative electrodes are composed of gel electrodes. The polymer binders are connected to each other to form a spatial network structure. The active particles and conductive agents are embedded in the network structure. The structural voids are filled with electrolyte, but the electrode viscosity is very high. Large, loses fluidity, and becomes an elastic semi-solid with a uniform appearance and a certain shape;
The separator is a gel electrolyte. The polymer polymers are interconnected to form a three-dimensional network structure. The pores are filled with an electrolyte that cannot flow to form a gel electrolyte, which conducts lithium ions and isolates electrons.
Semi-solid lithium metal battery
The negative electrode is composed of solid metal lithium and becomes a place for receiving lithium ions;
The positive electrode is composed of a solid porous electrode containing a solid electrolyte, and a small amount of liquid electrolyte filled in the pores, which also contains electrons and lithium ion conduction;
The separator is composed of a solid electrolyte, which can pass lithium ions and isolate electrons.
All-solid-state lithium metal battery
The negative electrode is composed of solid metal lithium and becomes a place for receiving lithium ions;
The positive electrodes are all composed of solid-state electrodes, which also contain solid-state electrolyte components that conduct lithium ions, which can conduct electrons and lithium ions at the same time;
The separator is composed of a solid electrolyte, which can pass lithium ions and isolate electrons.
Slurry battery
The positive and negative electrodes are suspension slurry, which contains active material solid particles, conductive agent solid particles and a large amount of liquid electrolyte, the solid particles conduct electrons, and the electrolyte conducts lithium ions;
The separator is composed of a solid polymer porous membrane, and the pores are filled with electrolyte, which can conduct lithium ions and isolate electrons.
flow battery
The positive and negative electrodes are both liquid electrodes, the active material is dissolved in the liquid, the electrolyte conducts ions, the current collector is a porous material, and an electrode reaction occurs on the current collector interface;
The isolation membrane is composed of a proton exchange membrane, which can only conduct hydrogen ions, while isolating electrons and other large ions.
Metal-Empty Battery
The negative electrode is composed of solid metal and becomes a place for receiving metal ions;
The positive electrode is composed of porous carbon absorbing oxygen in the air. The oxygen in the air gains or loses electrons to participate in the electrode reaction, and the electrode reaction only occurs at the interface of the carbon material;
The separator is composed of a common separator or a solid electrolyte, which can pass lithium ions and isolate electrons.
Therefore, the gel battery in the Ningde era may refer to the following two types:
(1) Gel polymer diaphragm battery: The diaphragm is a gel electrolyte, which contains a liquid electrolyte that cannot flow, but can transmit lithium ions; and the electrode is still a traditional electrode, a solid-state porous electrode, and the pores are filled with electrolyte;
(2) Gel electrode battery: the separator is a gel electrolyte, and the positive and negative electrodes are also gel. The electrolyte can conduct lithium ions.
The first is less difficult and has been reported in many literatures. What CATL mentioned is more likely to be the second battery. In fact, previous reports mentioned that Samsung has been promoting gel batteries. The biggest difference between gel batteries and ordinary lithium-ion batteries is the electrolyte of the battery. The main function of the electrolyte in the battery is to conduct ions. In the production process of lithium-ion batteries, the positive electrode and negative electrode are assembled and then injected, while the electrolyte of the gel battery has been added during the preparation of the pole piece, and the electrolyte of the gel battery is not in a liquid state. A jelly-like electrolyte (filled in the voids of electrodes and separators in an immobile state, and the polymer complexes with metal ions to form a gel state). With this electrolyte, the safety performance of the battery will be greatly improved.