A research team from China’s Nankai University has demonstrated that adding boron-based compounds to electrolytes significantly improves the performance and lifespan of lithium metal batteries (LMBs), addressing long-standing challenges such as dendrite formation, short cycle life, and low Coulombic efficiency.
LMBs, which offer energy densities exceeding 500 Wh/kg, are considered a breakthrough in energy storage. However, their commercial use is limited by safety and longevity issues. One effective strategy to overcome these barriers is electrolyte optimization — and boron additives have emerged as a promising, cost-effective solution.
The researchers highlighted several advantages of boron additives:
They help dissolve Li₂O at the lithium metal anode, reducing interfacial resistance.
In Li/CFₓ batteries, they break down LiF deposits in the cathode pores, boosting lithium-ion diffusion and high-rate performance.
At the cathode interface, boron compounds decompose to form a strong electrolyte interphase, enhancing long-term cycling stability.
Using electrostatic potential (ESP) analysis, the team identified tris(hexafluoroisopropyl) borate (THFPB) as the most promising additive. THFPB has a high ESP, allowing it to strongly attract small anions and improve electrolyte structure and interface behavior.
Spectroscopic analysis and molecular dynamics simulations further confirmed that THFPB enhances ion aggregation and interphase formation, especially for high-voltage cathodes like LiNi₀.₈Co₀.₁Mn₀.₁O₂. In battery tests, cells using THFPB retained 80% of their capacity after 150 cycles — a major improvement in stability.
Published in Science China Chemistry, this study demonstrates how boron additives (B-ads) can play a vital role in enabling the commercialization of high-energy-density lithium metal batteries by improving both efficiency and reliability through tailored electrolyte chemistry.
