Tesla's solid-state battery breakthrough: A pinch of baking soda solves the battery life issue

"Alchemist" Musk has just made a breakthrough in the field of solid-state batteries from 0 to 1.

Tesla's latest patent has been made public, discussing the improvement of battery cycle life with new materials.

How much improvement? Approximately around 10%.

Not very impressive?

But Tesla's new achievement is the first time a battery positive electrode material that was previously only theoretically feasible has been realized, opening a new door for the development of solid-state battery technology.

The application of new materials may rewrite the energy field once again.

What's impressive about Tesla's new battery materials?

First, let's look at the experimental results:

In 50 charge-discharge cycles, the battery made of Tesla's new positive electrode material has a total capacity decay of around 94%.

In comparison, the battery without Tesla's new formula has a decay of approximately 10%.

If calculated in absolute mileage, after 50 charge-discharge cycles, it is roughly equivalent to a driving scenario of around 20,000 kilometers.

So, if applied to a typical household car with at least 60,000 to 70,000 kilometers or even 100,000 kilometers of actual use, the improvement in battery decay with Tesla's new positive electrode material is actually quite limited. In other words, there is still a considerable distance to go before true mass production.

However, the impressive aspect of Tesla's new patent is that it has overcome a major challenge in the battery industry - the use of manganese-rich positive electrode materials.

The solution is to sprinkle a small amount of baking soda.

Will baking soda play a role in solid-state batteries?

Batteries, as we all know, mainly operate on the principle of redox reactions in a closed circuit.

During the battery discharge process, the battery's positive electrode, composed of a stable oxidant in the electrolyte, receives electrons in the reaction, meaning that electrons on the negative electrode reach the positive electrode through the electrolyte, reducing positively charged ions, releasing energy in the process.

Charging is the opposite oxidation reaction.

Positive electrode - electrolyte - negative electrode, since Volta invented the battery in 1799, this basic structure has never changed.

Any innovation related to batteries is essentially "alchemy" on these three components.

For example, the current popular concept of solid-state batteries replaces the liquid electrolyte in traditional batteries with solid electrolytes to achieve characteristics such as small size, large capacity, and fast charging and discharging.

However, the improvement in battery performance is not only at the electrolyte level, but also crucial in the innovation of positive and negative electrode materials.

For example, the most common ternary lithium or lithium iron phosphate batteries nowadays are named based on the positive electrode material In general, the positive electrode of a ternary lithium battery is lithium nickel cobalt manganese oxide (Li(NiCoMn) O2) or lithium nickel cobalt aluminum oxide, while the negative electrode is graphite material. The advantages are high energy density, fast charging and discharging speed, and light attenuation at low temperatures.

However, the disadvantages are also obvious, with high costs. The main issue lies in elements like cobalt, whose reserves on Earth are far less than manganese or nickel.

Therefore, the trend now is towards high nickelization of ternary lithium batteries. However, the global static extractable cycle of nickel mines is only about 35 years.

In terms of cost, lithium iron phosphate batteries have many advantages, but their endurance and anti-attenuation capabilities are not as good as ternary lithium batteries.

Is there a positive electrode material that can balance energy density and cost?

There are many current attempts, one of which is a rich manganese positive electrode material, such as LiMn2O4 - lithium manganese oxide, first artificially synthesized in 1981, is a positive electrode material with a three-dimensional lithium ion channel.

As for lithium, the reserves of manganese on Earth are much higher than cobalt and nickel (a difference of billions of tons and millions of tons), solving the cost issue.

In addition, lithium manganese oxide also has the advantages of high voltage, environmental friendliness, and high safety performance, and is recognized as the most promising replacement for lithium cobalt oxide LiCoO2 as the positive electrode material for the new generation of lithium-ion batteries.

In the next generation of solid-state battery technology, the combination of rich manganese positive electrode materials and composite lithium metal negative electrodes has become a widely anticipated route for mass production.

However, everything has a "but". Rich manganese positive electrode materials, including lithium manganese oxide, have a fatal flaw, which is rapid battery capacity decline and severe battery life attenuation.

The mechanism involves multiple factors. On one hand, during the charging and discharging process, manganese ions often dissolve into the electrolyte, leading to a decrease in manganese content in the material, causing voltage attenuation.

On the other hand, the structural damage of the positive electrode material is also an important factor in voltage attenuation. During the charging and discharging process, the rich lithium manganese-based positive electrode material undergoes volume changes, causing strain and fracture of the crystals, thereby damaging the material's structure and further causing voltage attenuation.

Therefore, methods can also be approached from these two aspects.

Tesla's new patent uses the method of doping an appropriate amount of transition metal ions to improve the material's structure and stability, reduce leaching and precipitation phenomena, and thereby reduce voltage attenuation In general, the doping of metal ions such as zinc, iron, and nickel is possible. However, considering the fundamental goal of "reducing battery costs," Tesla has chosen to dope magnesium (magnesium fluoride) and sodium (sodium carbonate).

Magnesium fluoride may not be commonly encountered by ordinary people and is generally used in metallurgy, ceramics, and optics. But we are very familiar with sodium carbonate, isn't it just baking soda~

Of course, the sodium carbonate mentioned here is an industrial-grade product, with a significant difference in purity compared to the baking soda in our kitchen.

Although Tesla's new patent has only taken a small step towards the adoption of manganese-rich cathode materials, its significance should not be underestimated: turning a battery cathode material that was previously only "theoretically" available into reality.

When used in current liquid batteries, it can significantly reduce costs and improve performance.

But more importantly, its application in future solid-state batteries: in terms of cathodes, low-cost, high-performance manganese-rich materials naturally meet the requirements. Now Tesla has proposed a low-cost solution to battery life issues.

The key breakthrough in cracking the seemingly impossible triangle of electric vehicle range, cost, and performance has always quietly laid in our kitchen.

Academician Musk now has a new title: Alchemist.

Author: You Ju Wu Che, Source: Intelligent Car Reference, Original Title: "Tesla's Solid-State Battery Breakthrough: A Pinch of Baking Soda Solves Battery Life Issues"