Lithium battery, lead-acid battery, graphene battery, which one is better? Why didn’t graphene batteries replace lithium batteries?
3 Types of battery
Lithium batteries are often referred to as lithium-ion batteries. The definition of a lithium ion battery is a device containing lithium ions that can convert chemical energy into electrical energy. Lithium-ion batteries are divided into lithium cobalt oxide batteries, ternary batteries, lithium manganate batteries, lithium iron phosphate batteries, and lithium titanate batteries (lithium titanate is a negative electrode material) due to the different positive or negative materials used.
The lead-acid battery often referred to is strictly a lead-lead dioxide battery. Spongy lead is the negative active material, and lead dioxide is the positive active material.
In fact, the currently claimed “graphene battery” on the market is an inaccurate concept. To be precise, it is basically adding a little graphene to the material to improve part of the performance of the lithium battery. It can be called a graphene-based lithium ion battery. . (PS. Graphene is hailed as the “king of new materials” by researchers and major media. It is known to mankind as a new nanomaterial with high strength, good toughness, light weight, high light transmittance, and good conductivity.)
Pros & Cons
Advantages: its durability is relatively poor, the life span is basically between 1 to 3 years, and the number of charging and discharging is only 300 to 500 times.
Disadvantages: It is safer than lithium batteries. Because there is no combustible inside the lead-acid battery, there will be no safety hazards such as deflagration.
Advantages: lighter in weight and smaller in size, so it is lighter and has better durability than lead-acid batteries. It can be used for 3-5 years, and the number of charging and discharging can reach 2000-3000 times.
Disadvantages: The biggest disadvantage of lithium batteries is poor safety and the possibility of explosion.
Advantages: good power storage, light weight, high durability, fast charging. The number of charging and discharging can reach 3500 times.
Disadvantages: Its craftsmanship is not mature enough, and the quality is uneven.
The main reason why graphene batteries are not mass-produced
1. All-graphene batteries are very expensive and difficult to prepare, making mass production almost impossible. Some amazing data released now basically come from graphene batteries with extremely high purity, which only appear in the concept stage or in the laboratory;
2. The role of “doped graphene battery” on lithium batteries is as a conductive agent or electrode lithium intercalation material, but compared with the low cost of traditional conductive carbon and graphite, the performance improvement brought by the former is not enough to attract various manufacturers;
3. The high specific surface area and other properties of the graphene material itself are incompatible with the current technical system of the lithium-ion battery industry(high production process requirements);
4. In addition, problems such as the impact of other materials (for example, silicon has a higher theoretical capacity in the negative electrode) and the high difficulty of the dispersion process, all restrict its application in lithium batteries.
In short, it is basically impossible for graphene batteries to replace lithium batteries in the short- to medium-term. Although “doped graphene lithium batteries” have certain application prospects, they have little effect and are not enough to shake the current situation. Pattern.
Supplementary knowledge points
What is a battery?
A battery is a device that converts chemical energy into low-voltage direct current.
Common batteries: zinc-manganese batteries, lead-acid batteries, nickel-cadmium batteries, zinc-nickel batteries, nickel-metal hydride batteries (metal hydride nickel batteries), lithium batteries, zinc-silver batteries, metal (aluminum, zinc, magnesium, etc.)-air batteries , Fuel cell, flow battery and so on.
The battery is generally composed of positive electrode, negative electrode, separator, electrolyte, shell and other parts.
How to name the battery?
Generally speaking, when naming the battery, the method of (-) negative electrode|electrolyte|positive electrode (+) is adopted.
For example, zinc-manganese batteries use zinc as the negative electrode active material and manganese dioxide as the positive electrode active material; cadmium-nickel batteries use sponge-like cadmium as the negative electrode active material, and the positive electrode is nickel oxyhydroxide active material.
In addition, it should be noted that in addition to the positive and negative active materials, some additives are added to the battery. For example, a conductive agent is usually added to improve conductivity. In order to improve the conductivity of the positive electrode active material, lithium-ion batteries will add carbon black, and lead-acid batteries will also add carbon black as a conductive agent.
What role does graphene play in the current lithium-ion battery system/lead-acid battery system?
If it is used as an active material, it is okay to call it a graphene battery.
Obviously, for the current commercial applications of batteries, graphene has not yet played this role. The main role played in lithium-ion batteries is still used as an additive-conductive agent. The most common is conductive paste, which takes advantage of the excellent conductivity of graphene. Graphene is added to lead-acid batteries, the negative active material is still spongy lead, the positive active material is lead dioxide, and graphene is only used as an additive.