Improved Lithium Battery Efficiency and Longevity Achieved through Electrolytes Enhanced by Boron Additives
Lithium metal batteries (LMBs) have the potential to revolutionize energy storage technology with an energy density of over 500 Wh/kg, but their practical application has been limited due to issues like lithium dendrite formation, short cycle life, and low Coulombic efficiency of Li plating/stripping. However, a new study suggests that boron additives could be a promising solution to these challenges.
Researchers from China's Nankai University explored four boron additives as candidates with various functional groups, using electrostatic potential (ESP) to find the best anion acceptors. Among the tested boron additives, tris (hexafluoroisopropyl) borate (THFPB) stood out as the most promising, endowed with a maximum electron potential.
The team found that boron additives can assist the dissolution of Li2O, reducing the interfacial charge transfer resistance of the Li metal anode. This improvement leads to better battery efficiency and a higher specific discharge capacity. Moreover, boron promotes the dissolution of LiF deposits within CFx pores, increasing the lithium-ion diffusion coefficient. Together, these effects help suppress lithium dendrite formation and improve cycle life, two major challenges for LMBs.
The study, published in the journal Science China Chemistry, also revealed that the addition of THFPB enhances ion aggregations in the solvation structure, contributing to the formation of a robust electrolyte-electrode interphase, especially for high-voltage cathodes. This contributes to the long cycling stability of these batteries.
Li∥LiNi0.8Co0.1Mn0.1O2 batteries using a thin Li anode, high-loading cathode, and 0.1 M THFPB added electrolytes maintained 80% of its capacity after 150 cycles, demonstrating the long cycling stability of these batteries.
While the study provides valuable insights into the role of boron additives in LMBs, there are still limited systematic investigations into how the electron-deficient properties of B-ads regulate the solvation structures of electrolytes and further impact the electrode-electrolyte interface. Future research in this area could lead to even more significant advancements in LMB technology.
Additive engineering is known as one of the most cost-effective methods for commercial applications in the optimization of electrolyte formulations. The team from Nankai University suggests that optimizing electrolyte formulations is an effective approach to overcoming the challenges faced by LMBs. With the potential benefits that boron additives offer, they could be a key component in the development of more efficient, safer, and longer-lasting LMBs for applications like electric vehicles and portable electronics.
[1] Li, Y., Wang, Y., Yuan, Y., Zhao, Y., & Li, W. (2021). Boron additives in lithium metal batteries: A promising strategy for high-rate and long-life electrode-electrolyte interphase engineering. Science China Chemistry, 64(1), 1-11.
[4] Li, Y., Wang, Y., Yuan, Y., Zhao, Y., & Li, W. (2021). Boron additives in lithium metal batteries: A promising strategy for high-rate and long-life electrode-electrolyte interphase engineering. Science China Chemistry, 64(1), 1-11.
The study published in Science China Chemistry reveals the potential of boron additives in revolutionizing the energy storage industry, particularly for Lithium metal batteries (LMBs). By improving battery efficiency, higher specific discharge capacity, and suppressing lithium dendrite formation, boron additives may lead to the development of more efficient, safer, and longer-lasting LMBs, which could have significant implications for applications such as electric vehicles and portable electronics. Moreover, the optimized electrolyte formulations using boron additives could be a key component in the advancements of LMB technology, resulting from additive engineering, an economical method for commercial applications in the industry.
