The binder, which holds electroactive material particles in electrodes, is essential to battery performance in Li-ion battery manufacturing. Traditionally, Li-ion batteries uses polyvinylidene fluoride (PVDF) or carboxymethyl cellulose as binders. However, there are limitations to the use of these materials. These include high preparation costs, insufficient adhesive strength, potentially hazardous and susceptible to agglomeration leading to degrading battery performance. Furthermore, PVDF is prepared using an organic solvent like n-methyl pyrrolidone, which is toxic and expensive.
The binders show various performance gains in areas such as gravimetric energy capacity, charge-discharge stability, and coulombic efficiency over conventional binders. Higher gravimetric energy capacity implies that the battery can be made lighter for the same energy requirement or it can power devices for a much longer duration. Together with high coulombic efficiency and charge cycle stability, Li-ion batteries using our binders is highly efficient and durable. The binders can be applied in Na-ion battery manufacturing. Although Na-ion battery is a relatively nascent technology, it has the potential to be a cheaper and more sustainable energy storage solution as compared to Li-ion battery. Sodium is a considerably more abundant element than lithium. In addition, by integrating this binder into current Na-ion battery, the battery life can be extended to more than 2000 rapid charging-discharging cycles without affecting its energy capacity. In contrast, the energy capacity of a Na-ion battery based on conventional binder materials will be reduced to 4% of its orginal capacity after 2000 rapid charging-discharging cycles.
This technology is related to the development of binders which are made using common and cheap constituents such as extract from the bark of Neem trees, wheat powder or glue in different weight ratios. All of these substances are soluble in water. Hence, there is no need for expensive and toxic organic solvents in the preparation steps. With other manufacturing conditions being moderate, the binders can be mass produced at low cost without compromising battery performance.
The market for Li-ion batteries is growing exponentially with the increasing demand for electric vehicles and alternative energy. The Li-ion battery market is expected to grow to $43 billion USD by 2020. Li-ion batteries are smaller, lighter and more powerful than traditional batteries. They also have no memory effect and a very low rate of discharge when not in use. All these characteristics lead to the proliferation of Li-ion battery technology.
Improvement in gravimetric energy Increase in number of charge cycles of battery Cost-effective due to cheap and abundant raw materials Environmentally friendly Applicable to Li-ion or Na-ion battery manufacturing