Battery Chemistries

LFP benefits:

LFP can be charged to 100% of its capacity
Higher discharge cycles
Lower cost than NMC and NCA batteries
Safer and more robust with long service life than flammable NMC and NCA materials

LFP is based on lithium, which is associated with supply challenges and price volatility, we are also developing sodium Ion batteries (SIB or NIB) for ESS applications. Sodium is an abundant element in the earth's crust, providing a more stable and sustainable alternative. Commercialization is planned for mid-2024.

Lithium Iron Phosphate Battery (LiFePo4 or LFP)

Sodium-Ion Battery (Na-Ion, NIB or SIB)

An LFP is a cost-effective and safe lithium-ion battery

The Li-Ion battery family contains different battery chemistries named after their cathode; LFP is part of that family. And while an LFP is a Li-Ion battery, not all Li-Ions are LFPs. Other lithium-ion batteries include Nickel Manganese Cobalt oxide (NMC) and lithium nickel cobalt aluminium oxides (NCA). Both are already utilized heavily in electric vehicles.

The “F” in LFP stands for iron

Batteries are typically named after the chemicals used in the cathode, and an LFP battery uses a cathode material made from the inorganic compound lithium iron phosphate, with the formula LiFePO4. The “F” comes from “Fe,” the periodic table of elements chemical symbol for iron. Fe is derived from the Latin word for iron, ferrum. You may also see an LFP referred to as a lithium ferro phosphate battery.

LFPs can be charged to 100%

Charging an NMC or NCA to 100% puts the batteries in an extreme state of charge. Because batteries turn chemical energy into electricity, a battery is inherently unstable when fully charged. Overall, it is considered best practice to avoid a very high and meager charge, with 80% being the standard battery capacity for an optimal lifetime.

However, LFP batteries are an exception to this charging standard. LFPs have 100% of their capacity available, meaning they can be fully charged without causing accelerated battery degradation. This is thanks to the battery’s cathode.

LFPs are a lower-cost option

Manufacturing NMC and NCA batteries require nickel and cobalt, two materials that come at a pretty penny to extract. The cost of buying both materials is expensive already. Still, the increasing nickel shortage and cobalt production being stretched to its limits pose a challenge to manufacturing NMC and NCA batteries and making them affordable.

LFP batteries, on the other hand, currently bypass supply chain issues and inflated prices because nickel and cobalt aren’t needed for the cathode. An LFP’s cathode is made from earth-abundant materials. Lithium iron phosphate is a crystalline compound that belongs to the olivine mineral family. Because the olivine family is a primary component of the Earth’s upper mantle, LFP is more readily available for extraction at a lower cost.

LFPs are safe and robust, with long service life

LFP batteries are extremely safe from a fire and explosion perspective and making them a perfect choice for EV, Energy Storage indoors and outdoors. Service life, both calendar life and the number of charge/discharge cycles outperform other Lithium chemistries.

Sodium:

Despite the dominance of lithium-ion batteries (LIBs) in the energy storage industry over the past two decades, sodium-ion batteries (SIBs) are likely to replace them in the future, driven by their promising characteristics:

Sodium is cheaper than lithium
Its chemical behaviour is similar to lithium’s
The irreversible capacity of carbon anodes in SIBs is less than in LIBs
Sodium is abundant in the earth's crust and in seawater
It can be transported safely and at a lower cost.

Why discuss alternatives to LIBs?

While LIBs will likely continue to drive the energy storage industry in the next future, there are some concerns regarding them: (1) safety hazards, as they contain flammable electrolytes and explode if damaged or overcharged, (2) there is a shortage of key inputs, and (3) they are expensive.

Importantly, more than the shortage of key inputs – lithium (ca: 5% of LIB volume) and cobalt (ca: 20% of LIB volume) – mining constraints put supply-side pressure on the pricing of LIBs due to environmental concerns and domestic instability.

LIB prices fell 87% from 2010 to 2022, primarily due to the introduction of new chemistries and advanced manufacturing techniques. However, with lithium and cobalt being the key inputs, LIB prices will likely remain far higher than those of potential alternatives.

Layered oxides

Material introduction: The structure of the layered transition metal oxide cathode material for sodium batteries is similar to that of the ternary cathode materials for lithium batteries. The molecular formula is NaxMO2, where M represents transition metals such as nickel, iron, and manganese. In the intercalation and extraction process of sodium ions, different binary, ternary or even multi-component layered transition metal oxides can be prepared by doping or substituting different transition metal elements by taking advantage of the good adjustability of its structure.

Characteristics: Excellent rate capability, impressive performance in low temperatures, and a cycle life of 3000-5000 cycles. The energy density is above 130Wh/kg

Applications: Power batteries for low-speed vehicles, automotive start-stop batteries, and backup power in low-temperature areas.

Polyanion

Material introduction: polyanionic materials, and polyanionic compounds are closer to the structure of lithium iron phosphate. Polyanionic compounds exhibit high thermal stability, safety and cycle performance, and the cycle performance can reach more than 10,000 times.

The energy density of the new generation of products is above 110Wh/kg. The cycle life of the full battery is as high as 10,000 times, and pilot production has been achieved. The next generation of products is expected to further increase the energy density, and the mass application of large-scale energy storage can be realized in the future.

Characteristics: High safety, long lifespan of over 1,000 cycles. The energy density is above 110Wh/kg.

Applications: Commercial and industrial energy storage, grid-scale energy storage.