Why Lithium-ion Batteries are Popular?
The main reason you’ve heard the term “lithium-ion battery ”before is energy density; a LIB setup can pack a lot of power into a very small space. More than that, “Li-on” batteries offer decent charge times and a high number of discharge cycles before they die. If you use a pure lithium metal at the electrodes, you’ll get much higher energy storage, but no ability to recharge — depending on your choices for electrodes, you can powerfully affect your battery’s performance. Among other things, energy density is related to the number of lithium ions (and thus electrons) the electrodes can hold per unit of surface area.
These lithium-iron phosphate batteries show promise for everything from electric cars (likely) to storage of grid power (less likely), but when it was originally introduced, LiFePO4 showed little promise for battery tech. In its pure form, lithium-iron phosphate shows poor electrical abilities — but crush it up into nanoparticles and coat it with carbon and it seems the story changes quite a bit. The incredible jump in ability when turned into nanoparticles is described as a major surprise for battery researchers, and a major win for nanoscience.
The main reason for excitement over the new nano-cathode, beyond its impressive-but-not-amazing storage and discharge abilities, is that it discharges at a totally uniform voltage. This means batteries needn’t incorporate devices to regulate that voltage, which could make them cheaper and smaller, and it also allows them to discharge at full voltage until totally empty. It does this, we now know, by creating a zone called a Solid Solution Zone (SSZ), a buffer area of low lithium density that seems to soften the harsh boundary between charged (LiFePO4) and discharged (FePO4) portions of the electrode during use. This seems to be behind the material’s amazing abilities, and pumping up this SSZ through design could extend make lithium-ion tech last even longer.
Technology does seem to be coming for this aging battery standard, however, and it will need some major upgrades to stay with the times. It’s getting them, with huge design upgrades that hold a lot of promise. Still, everything from improved capacitors to super-batteries based on cotton could supplant lithium as the king of energy storage — we may find that improvements in our understanding of conventional batteries are simply too little too late.