Kerry Wan/ZDNET
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**ZDNET’s Key Takeaways**
Solid-state batteries present a range of transformative advantages when compared with conventional lithium-ion technology. Chief among these are markedly enhanced safety and significantly extended lifespan. Yet, despite their promise, the technology—while advancing swiftly—is still not mature enough to satisfy the enormous industrial demand for billions of units annually.

Not long ago, I had the opportunity to examine a portable power bank that stood apart from typical models due to its use of a solid-state battery at its core rather than the standard lithium-ion cell. From this hands-on experience, several of the technology’s promised benefits became evident: greater energy density, improved physical and chemical stability, and the potential for a much longer operational life. To vividly illustrate just how stable and resilient these batteries can be, I conducted a rather extreme test by intentionally puncturing a fully charged battery with a metal screwdriver. Surprisingly, aside from releasing a few faint trails of smoke—a minimal reaction compared to what one might expect—nothing dramatic occurred. The reduced volatility of the cell clearly demonstrated one of the principal advantages of this next-generation design.

**Why, then, are our smartphones, laptops, and everyday smart devices not yet powered by this superior technology?** Before answering that question, we must first establish what distinguishes a solid-state battery from the Li-ion batteries that currently dominate the market.

**Solid-State Versus Lithium-Ion: Understanding the Difference**
At the most fundamental level, solid-state batteries represent an advanced category of rechargeable power sources that replace the liquid or gel-based electrolytes found in lithium-ion batteries with solid materials. These solid electrolytes, often composed of dry ceramic or similarly rigid compounds, act as the medium through which charge flows between the anode and cathode. In contrast, lithium-ion batteries rely on electrolytes composed of lithium salts dissolved in a mixture of volatile, highly flammable organic solvents. This distinction alone has far-reaching implications for both safety and performance.

Because solid electrolytes are non-flammable and chemically stable, they dramatically reduce the risk of combustion or thermal runaway—failures that have historically plagued lithium-ion systems. In addition, solid materials can allow for tighter energy packing, offering higher energy density and potentially ushering in devices that run longer on a single charge without increasing size or weight. Furthermore, since solid electrolytes are less prone to degradation over repeated charging cycles, they can substantially extend a battery’s functional lifespan.

Beyond safety and energy retention, another critical performance benefit emerges: solid-state batteries generally recharge faster than their liquid-based counterparts. This means the same power pack can achieve full capacity more quickly, making the user experience more convenient and less dependent on lengthy charging sessions. For example, the power bank I tested not only felt cooler during operation but also charged at a noticeably more efficient rate than most lithium-ion models.

**If solid-state batteries are superior in almost every respect, why hasn’t the world already embraced them universally?** The answer lies not in theoretical capability but in the complex economic and logistical realities that underpin modern electronics manufacturing.

**A Matter of Scale: Billions of Batteries Each Year**
Cost and manufacturability remain the greatest bottlenecks. Lithium-ion batteries have enjoyed over three decades of industrial refinement. During that time, global supply chains have been optimized to produce billions of cells each year with extraordinary efficiency. That’s not an exaggeration: Apple alone sold roughly a quarter of a billion iPhones in a single year, every one of them requiring an inexpensive yet dependable power cell. When one extends this calculation across the entire smartphone market—estimated between 1.25 and 1.6 billion units annually—and adds other categories such as laptops, earbuds, wearable devices, portable power banks, e-cigarettes, and, most notably, electric vehicles (each of which contains thousands of individual battery cells), the scale of production becomes almost incomprehensible.

In comparison, solid-state battery manufacturing remains in its infancy. Production lines capable of fabricating these cells at scale are exceedingly rare, and the materials and manufacturing processes themselves are technically intricate. Achieving consistent quality and uniform output proves challenging, leading to lower production yields. These low yields, when combined with limited factory infrastructure, result in a steep price disparity—solid-state batteries currently cost four to eight times more than equivalent lithium-ion units. For devices produced by the millions, such a premium is unsustainable.

Moreover, solid-state cells introduce additional engineering challenges. They tend to be more sensitive to mechanical stress, including vibrations common in portable electronics, and they can expand slightly during use—a property manufacturers must carefully manage to prevent structural damage or performance degradation. Each of these hurdles compounds the difficulty of integrating solid-state batteries into existing device architectures designed around the predictable behavior of lithium-ion systems.

**The Road Ahead: When Will Solid-State Technology Arrive at Scale?**
Despite these obstacles, the general consensus within the energy-storage industry remains optimistic. The problems that currently constrain production—whether technological or economic—are viewed as temporary, solvable through continued research, advanced materials science, and manufacturing innovation. Incremental improvements are already underway, and numerous companies have announced pilot projects aimed at scaling solid-state technology in the coming years.

However, another subtle factor slows adoption: lithium-ion batteries have become remarkably good. Continuous refinement has resulted in cells that are inexpensive, efficient, safe under normal use, and capable of recharging at respectable speeds. For most consumers, the performance of today’s lithium-ion batteries satisfies everyday needs, reducing the urgency for immediate change. Manufacturers, too, are understandably cautious about shifting to a new system that requires entirely retooled production processes.

Industry experts anticipate that true large-scale solid-state production will emerge during the early 2030s. Only once economies of scale, automation, and material optimization intersect will solid-state batteries begin to displace lithium-ion as the dominant standard across consumer electronics and electric vehicles alike. Until then, lithium-ion—despite its flaws—will remain the backbone of our portable, battery-powered world.

Sourse: https://www.zdnet.com/article/why-solid-state-batteries-not-on-iphone-yet/