Chinese researchers are making significant strides in enhancing the lifespan and efficiency of lithium batteries through the innovative use of boron additives. This development could revolutionize energy storage for electric vehicles, consumer electronics, and large-scale infrastructure, addressing critical issues like dendrite formation, limited cycle life, and low Coulombic efficiency in advanced lithium metal batteries.
The Role of Boron in Next-Generation Batteries
Boron and its compounds have been extensively studied in the development of lithium batteries for decades, owing to their unique properties. Researchers are now leveraging boron’s electron deficiency to create new nanostructures and material science breakthroughs. The addition of boron-based materials offers multiple benefits across various components of lithium batteries.
Mitigating Lithium Dendrite Formation
One of the primary challenges in lithium metal batteries (LMBs) is the formation of lithium dendrites, which can lead to short circuits and significantly reduce battery life and safety. Chinese research teams have found that electrolytes containing boron additives can effectively mitigate these critical challenges. For instance, a boric acid treatment on a lithium anode has been shown to suppress dendrite growth and enhance cycling performance. Similarly, hexagonal boron nitride (h-BN) coatings on separators can effectively suppress lithium dendrite growth.
Enhancing Charge Transfer and Ion Diffusion
Boron additives exhibit a strong electron-deficiency, which assists in the dissolution of Li₂O, thereby reducing the interfacial charge transfer resistance of the lithium metal anode. Furthermore, by dissolving LiF deposits within CFx pores, boron additives can increase the lithium-ion diffusion coefficient, leading to largely improved specific discharge capacity and enhanced high-rate performance in Li/CFx batteries. This improvement in ion kinetics is crucial for faster charging and discharging capabilities.
Stabilizing Cathode-Electrolyte Interphases
The oxidative decomposition of boron additives at the cathode interface facilitates the formation of a robust cathode electrolyte interphase. This stable interphase is vital for the long cycling stability of high-voltage cathodes, a key factor in improving overall battery longevity. Boron lithium compounds are effective in assisting the formation and stability of the interfacial layer between the electrode and electrolytes, whether introduced as electrolyte additives or directly applied.
Research and Application in China
Chinese institutions and companies are at the forefront of this research. A team from Nankai University has been instrumental in identifying how boron additives can address the critical challenges of LMBs. Their research explores various boron additives, with tris(hexafluoroisopropyl)borate (THFPB) showing particular promise as an anion acceptor due to its high electrostatic potential.
In a related development, Lithium and Boron Technology, Inc. (LBTI), a Chinese company, announced a breakthrough in lithium carbonate extraction technology in 2021. This proprietary sorbent processing technology allows for efficient, environmentally friendly, and cost-effective extraction of lithium carbonate from mineral-rich brine water, such as that found in the Dachaidan Salt Lake in Qinghai Province, China. This technological advancement aims to support the rapidly growing demand for lithium carbonate in electric vehicle and energy storage batteries.
Beyond Boron: Broader Battery Innovations in China
While boron additives are a significant focus, Chinese researchers are also pursuing other innovative methods to extend battery life and performance. Researchers at Fudan University in Shanghai have developed a method to extend the service life of lithium-ion batteries by restoring lost lithium ions, boosting the average number of charging cycles from 1,500 to 12,000. This “precision treatment” involves injecting a novel lithium-ion carrier molecule, developed using AI and organic electrochemistry, into degraded batteries. This non-invasive process preserves cell integrity and has the potential to increase battery lifespans to an unprecedented range of 12,000 to 60,000 cycles.
Furthermore, Chinese researchers are actively working on solid-state battery technology, seen as a revolutionary step for energy storage. Teams from Tongji University and Huazhong University of Science and Technology have identified a mechanism behind solid-state lithium battery failures related to the cycle fatigue of the lithium metal anode, providing a framework for predicting battery life cycles and designing longer-lasting systems. These breakthroughs underscore China’s significant investments in electrochemical research and its ambition to lead the next generation of battery technology.
