What is the role of lithium-ion batteries in sustainable energy?
There are basically two major contributions from lithium-ion batteries to the development of sustainable energy:
- Optimize the management of electricity generated from renewable energy. A typical example is the energy storage scheme in large outdoor PV generator systems. The scale of power generated from solar cells usually depends on the condition of sunlight. The PV generator system will need to rely on additional power management design to stabilize the output of power so that the electricity can be directly and efficiently utilized. Lithium-ion batteries can provide additional energy to compensate when there is a lack of power or can store excess energy under peak conditions.
- Support the use of sustainable energy in a more economic, reliable and efficient application model. For example, the lithium-ion battery power system in a fuel-cell electric vehicle (FCEV) can minimize and stabilize the current flow output from a fuel cell to extend the use life of the FCEV’s power system. In addition, the hybrid design of lithium-ion batteries in FCEVs can greatly reduce their cost. In the future, sustainable energy methods may become more advanced and reduce the current weaknesses of FCEVs. However, it still may take decades to develop these techniques so that they become more mature and popular and can be provided at a reasonable cost. With the aid of lithium-ion batteries (or similar kinds, like Ni-H and lead-acid), the development and commercialization of those techniques can be accelerated.
How are lithium-ion batteries different from traditional batteries?
There are some similarities and differences between lithium-ion batteries and other types of chemical batteries. Before lithium-ion batteries were widely used for small electronic, mobile and stationary applications, the most popular battery types were Ni-H, Ni-Cd and lead-acid batteries. All types of chemical batteries are similar in that they generate electricity via an oxidation-reduction reaction between an anode (i.e., positively charged electrode) and a cathode (i.e., negatively charged electrode). However, what makes lithium-ion batteries different is their intrinsic material properties.
Different battery types typically show different strengths and weaknesses in performance. For example, Ni-H and Ni-Cd batteries were once very popular as portable power sources for small electronics. However, memory effect (i.e., the variation in battery performance depending on how people use it) has become a big concern in performance, and users commonly worry that the battery could potentially die earlier than expected. There is also concern about environmental issues related to Ni-Cd, as cadmium is a toxic substance. Regarding the lead-acid battery, there is no doubt it is a mature, low-cost and safe battery type suitable for large battery applications. However, low efficiency in charging and discharging and low energy density are its weaknesses, which is why researchers are always looking for a substitute battery for industrial, stationary and energy storage applications.
Excellent energy and power density, lack of memory effect, and absence of environmental concerns have made lithium-ion batteries the primary substitute for traditional batteries and the dominant battery type to address most off-grid applications. However, lithium-ion batteries are not perfect, as there are still some safety concerns. Only after these safety issues are effectively addressed can the use of lithium-ion batteries be further advanced to open the market for mobile, stationary and other large battery applications.