Is it supply chain technology or self-developed? The secret behind the soaring battery life of domestic mobile phones

PConline太平洋科技

2024-05-27 17:56Posted in Guangdong Digital Creators

Ever since smartphone screens have gotten bigger and bigger, battery life hasn't seemed to be getting better, and the experience of charging once every few days in the era of feature phones is gone.

Then again, how long did the screen time of the previous feature phones last, 1 hour a day? And today's smart phones, with so many functions, such a big screen, and they have to stay online all the time, and the screen time is at least five or six hours, and one charge a day seems to be very powerful!

If you have used the domestic flagship models released in the last year, you will find that their battery life has made great progress, and they can basically be charged once every two days. In just over a decade, how has the mobile phone battery developed to its current level? In the past year, manufacturers have successively launched Qinghai Lake battery, blue ocean battery, Jinshajiang battery and other technologies? Why is the timing so close?

▲ Image source Xiaomi

The leap from nickel to lithium

The new generation of mobile phone users may not have heard of the magical theory that charging the battery before it runs out will make the battery capacity smaller, and this is one of the major drawbacks of nickel-cadmium batteries used in early mobile phones - the memory effect. Later, nickel-metal hydride batteries appeared, and the memory effect was significantly improved.

Until around the turn of the millennium, lithium-ion batteries underwent major innovations in materials and manufacturing techniques, with significant cost reductions, increased energy density, and the problem of battery memory effects being solved. These improvements have made lithium-ion batteries quickly become the standard choice for the mobile phone industry, and the entire industry has officially entered the era of lithium batteries.

Conventional lithium batteries limit the shape and size of the battery due to the use of liquid electrolytes. Because it is necessary to ensure that the electrolyte remains stable inside the battery while also preventing leakage and corrosion, a rigid housing is often used, which limits the shape design of the battery. In addition, liquid electrolytes may swell or burn under high temperatures or overcharges.

Later, it evolved into the widely used lithium polymer battery in the industry, using a gel or solid electrolyte, using aluminum film packaging, more free in volume and shape, and can flexibly adapt to electronic products with increasingly compact internal space. And the thermal and mechanical stability of the battery is also better, which reduces safety risks.

After the development of mobile phone battery technology to lithium polymer, there has been no significant upgrade for a long time, because the limitations of graphite anode in lithium battery have gradually emerged.

The theoretical specific capacity of the graphite anode is limited to 372mAh/g, and the diffusion rate of lithium ions is low, which limits the improvement of battery energy density and fast charging ability.

In addition to the performance shortcomings of the material itself, natural graphite, as a non-renewable resource, also faces many problems.

According to the United States Geological Survey (USGS), global graphite reserves were about 300 million tons in 2020, and at the current rate of mining, global graphite resources are expected to be depleted by 2050. At the same time, natural graphite, as a natural resource, is affected by geopolitical factors like natural gas and oil, and the supply is not stable.

Artificial graphite can avoid the problems caused by natural graphite to a certain extent, but the production process of artificial graphite requires a lot of energy and produces a large amount of wastewater, if not properly treated, it will cause serious soil and water pollution, contrary to the "new energy" called "environmental protection".

And then there's the most important factor in business: profit. With the current production process, artificial graphite of the same purity is 20-30% more expensive than natural graphite. As natural graphite resources become less and less, the price of natural graphite will become more and more expensive.

Therefore, finding alternative materials for graphite has become one of the most important development directions of the lithium battery industry.

The next generation of lithium battery: silicon carbon anode

Whether it is Qinghai Lake Battery, Blue Ocean Battery or Jinshajiang Battery, they all invariably mention "silicon carbon anode" in their publicity, which is also a key technology to solve the current battery problem.

The disadvantages of graphite as an anode material mentioned above, so is there any other material that can replace it, and there is, that is, silicon.

Silicon, as an anode material, has a theoretical specific capacity of up to 4200mAh/g, which is almost 11 times that of graphite. This means that lithium batteries using silicon anodes can theoretically significantly increase energy density, thereby extending the life of the battery and reducing the number of recharges.

However, silicon materials can undergo volume expansion of up to 300% during charging and discharging, and this significant volume change can lead to the rupture of the electrode material, thus reducing the cycle life of the battery.

▲ Source: Group14

To overcome this challenge, scientists have developed silicon-carbon composites. By combining nanosilicon nanoparticles with carbon materials, the stability of carbon materials can be used to suppress the volumetric expansion of silicon and improve the overall electrical conductivity through the conductive network of carbon.

Although silicon carbon anode technology has great potential to improve battery performance, its process difficulties remain. The preparation of silicon-carbon anodes requires precise control of the nanostructure of the material, as well as ensuring a uniform distribution of silicon and carbon. In addition, first-time efficiency and cycle stability in the battery manufacturing process are also key challenges to overcome.

Group14 vs ATL

In fact, as early as the 70s of the last century, silicon carbon anode battery technology has passed the feasibility verification, why did we not see a large number of consumer terminals adopting it until nearly a year?

This has to mention two companies, one is the well-known ATL (new energy), that is, the parent company of Ningde New Energy and Dongguan Xinnengde, and the other is the start-up company Group14.

▲ Source: Group14

On February 28, 2023, Group14 officially announced that it has supplied SCC55 material to ATL to power 3C products such as next-generation smartphones, and said that mobile phones using SCC55 battery materials will be available soon.

A week later, on March 6, Honor released the world's first smartphone equipped with silicon carbon anode battery technology - the Magic5 series, and industry media TechInsights also confirmed that the implementation of this technology is led by Group14's battery material product SCC55.

▲图源微机分WekiHome

We can also see in the video of the well-known dismantling of the Up main microcomputer sub-machine that whether it is Qinghai Lake battery, Blue Ocean battery or Jinshajiang battery, they are all produced by Xinnengde Company and use ATL cells. We can basically guess that the silicon carbon anode technology they use uses Group14's SCC55 material.

Why does it have to be the SCC55 of Group14? At present, there are not many companies that can mass-produce silicon carbon anode materials, and Group14 is the largest share of them.

Rising Star: SCC55

Before we get into the SCC55 presentation, let's take a brief look at what Group14 is.

Silicon is in 14th position in the periodic table, which is where the "14" in Group 14 comes from. Founded in 2015, the company is committed to converting lithium-ion batteries into lithium-silicon anode batteries to help solve energy storage problems, and has received investment from ATL, SK Materials, Porsche and other companies, with a cumulative amount of more than 600 million US dollars, and is a hot tomorrow star in the lithium battery industry.

▲ Source: Group14

As an emerging technology, many companies at home and abroad are tackling key problems, and they have also taken a lot of financing, and even many of them have released very amazing parameters on the "PPT". However, many of them are still in the laboratory state or even the theoretical state, and are far from meeting the requirements of mass production.

Group14 is almost the first to achieve mass production, and it also has incomparable advantages in terms of application.

▲ Source: Group14

What makes the SCC55 unique is its structural design. The material consists of silicon nanoparticles embedded in a carbon scaffold. This structure allows the silicon particles to be in full contact with the electrolyte, thus improving the charging and discharging efficiency of the battery. In addition, the carbon bracket provides mechanical support to prevent the silicon particles from expanding and contracting during charging and discharging.

As a result, SCC55 silicon anode batteries have 50% higher energy density than conventional lithium-ion batteries, and charge faster, theoretically only taking a few minutes.

The SCC55 material is also easy to bring into production, from coin cells to pouch cells, allowing manufacturers to seamlessly incorporate SCC55 into any lithium-ion battery production line, gigafactory, or battery design without the need to readjust the process.

Rather than concept, large-scale mass production is the foundation of profitability.

Group14's two-step process makes it simple to scale, first synthesizing carbon to create a carbon scaffold, then creating silicon inside the scaffold and adjusting the internal voids to finally form the magical SCC55. The specific process details have already been applied for global patents by Group14 and have become the cornerstone of its business empire.

▲ Source: Group14

Group14 has also designed a process that can be easily replicated to build factories of all sizes (BAM factories) where they are needed. Each module is self-contained and can produce up to 10 GWh of material per year. It is also possible to combine any number of modules as needed to form a BAM plant of any size.

▲ Source: Group14

In terms of production capacity, Group14's BAM-1 plant in Woodinville, Washington, USA, currently supplies more than 65 customers, representing 95% of the global battery production market, and is also deploying BAM plants in Asia, Europe and other regions. It is certain that the BAM-1 plant has produced more than 10 GWh, which can meet the needs of about 10-200,000 electric vehicles.

If the production goes smoothly, the BAM-2 plant in Washington will double the capacity of BAM-1 and will become the world's largest advanced silicon anode battery technology plant in 2024.

Write at the end

There are often people in the machine circle who ridicule: it's not all supply chain technology, what is self-developed. Judging from the results, the silicon carbon anode cells of these companies are all from ATL, and there is a high probability that they are made of SCC55 materials, which seems to be the case.

But in fact, the communication between the supply chain and manufacturers is not one-way, and the application of many materials and technologies is often the result of the joint efforts of both parties. By analogy, supply chain technology is like an ingredient, and the final product depends on the chef's cooking techniques and seasoning.

▲ Image source vivo

Taking the battery life discussed in this article as an example, the mass production application of silicon carbon anode batteries is the key. The theoretical energy density of the silicon carbon anode is much higher than that of the traditional graphite anode, which can greatly improve the battery life. Group14's SCC55 material is one of the most representative silicon-carbon anode materials at present, with excellent performance and mass production capacity.

At the same time, various mobile phone manufacturers have also optimized the battery packaging process, power management, system scheduling, etc., and finally let consumers get their hands on the mobile phone with excellent battery life.

As for the question mentioned in the title of this article, everyone can have their own understanding.

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