Distinguish the negative and positive electrode of lithium ion battery

The judgment method of battery electrodes: (1) Use the multi-meter to test voltage profile, connecting a multi-meter red pens to one end of the battery, and multi-meter black pens connecting the other end of the battery. If the multi-meter pointer deflection is positive (turn right), it means that the end connecting multi-meter red pen is the positive electrode and it is marked by a symbol of (+), while the end of the battery connecting black pen is cathode and it is marked by a symbol of (-). Otherwise, If the multi-meter pointer deflection is reverse direction (turn left), it means that the end connecting multi-meter black pen is the positive electrode, while the end of the battery connecting red pen is cathode.

2. Is to use two wire, a diode, a small flashlight bulbs to judge the anode, the batteries are method is to use a wire one end connected to the battery one end any of the other end connected to the diode, the other end of the diode connect one end of the small bulbs, on the other side of the small bulb connected another one end of the wire, wire connected at one end of the left, on the other side of the circuit, thus formed at this time if the light bulb, that is the right connection. Batteries and diode connected at one end is the positive (+) of the battery, the battery is on the other side of the battery negative (-). At this time if the bulb is not bright, put one end of the battery or diode invert,

But said a little science method, can put the battery to an ammeter circuit, if the current meter to positive direction normal deflection is battery positive terminal on the positive, negative answer is battery cathode; If the ammeter reversed deflection of the anode to the cathode, the cathode anode. Or in electrolyte solution, plus or minus attraction so, anionic gathered is positive, positive is negative (recommended use colored electrolytes such as potassium permanganate, color after the power supply will be separate, purple side is the anode, the end is colorless cathode)

1, see screen printing: screen printing is screen printing, general is left is right;

2, look at both ends: shape have raised side is positive, the flat is negative;

3, multi-meter measurement: red and black pens and, according to the red line is under the condition of positive +, black is -, displays is red pens and under the condition of negative electrode, black is the corresponding + electrode;

4, see appearance, change model in general, the prototype battery insulation on both ends ensure, concave ring at one end, end have no, have a plenty of positive, not negative;

5, some manufacturers do not according to the battery standard, logo production, then the actual measurement and consulting the factory, ask for the specifications;

Positive electrode (cathode) is cobalt acid lithium and many ingredients, these substances on the aluminum foil.

Cobalt acid lithium is the main body part, to create a chemical reaction of charging and discharging (and graphite reaction, below)

Add the ingredients to improve the performance of the battery, such as reduce the internal resistance, increase capacity, and improve the impact resistance, anti-explosion and fire prevention performance, especially added flame retardant materials.

Nano-scale carbon negative electrode (anode) is graphite (powder), these things on the copper foil.

Reaction equations as follows:

On a positive response for

LiCoO2 = = Li1 - charging xCoO2 + Xli++ Xe (electronic)

Reaction to occur on the cathode

6C+XLi++Xe=====LixC6

How, is professional enough?

Attach:

A qualified lithium ion batteries on the safety performance should meet the following conditions:

(1) short circuit: no fire, no explosion

(2) charging: no fire, no explosion

(3) the hot box test: no fire, no explosion (150 ℃ temperature 10 min)

(4) Needle thorn: no explosion (with 3 mm Ф penetrate cells)

(5) Tablet: no fire, no explosion (10 kg weight from 1 m high at the battery)

Burned (6): no (a gas explosion flame barbecue battery)

So till now, the process improvements, qualified the lithium battery already very safe.

If you have any other lithium battery of questions, please leave a message to my blog. I am a lithium battery manufacturing engineers.

Lithium ion battery principle and technological process

A, principle

1.0 The anode structure

LiCoO2 (cobalt acid lithium) + conductive agent (acetylene black) (PVDF) + + adhesive fluid (aluminum foil) positive

2.0 the cathode structure

Graphite + conductive agent (acetylene black) + thickening agent (CMC) + binder (SBR) + fluid (copper foil) negative

3.0 working principle

3.1 the charging process

Pictured above a power source to recharge the battery, on the positive electron e running on the cathode through an external circuit is lithium ion Li + "jump" from the positive electrolyte, "climb" diaphragm winding holes, "swimming" arrived at the cathode, and would have run to come over together.

On a positive response for

LiCoO2 = = Li1 - charging xCoO2 + Xli++ Xe (electronic)

Reaction to occur on the cathode

6C+XLi++Xe=====LixC6

3.2 The battery discharge process

Electric discharge includes constant current and constant resistance discharge. Constant current has a variable resistance in the external circuit so that the current can changes with voltage. Constant resistance discharge has a resistor in the external circuit to pass through electric charge. Therefore, as long as the cathode electron can't run away from the cathode to the anode, the battery will not discharge. Electronic and Li + make action at the same time in the same direction but different route. During discharging, electrons come from the cathode through electronic conductor to the anode, while lithium ion comes from the cathode through electrolyte, passes the separator, and finally runs to the anode. It would combine the electrons.

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