Achieving high performance lithium-ion batteries with nanodiamond-enhanced propylene carbonate-based electrolyte cycling at low temperature

Low-temperature lithium-ion batteries (LIBs) suffer from capacity decay and impaired recharge ability due to electrolyte freezing and insufficient solid electrolyte interface (SEI) properties. Propylene carbonate (PC) offers advantages like high dielectric constant, low freezing point and cost-effectiveness, while the inherent challenges of poor compatibility with graphite and high viscosity impede its practical application. Herein, by incorporating nanodiamonds (NDs) into PC-based electrolytes, the low-temperature rechargeability of graphite anode is boosted. Experimental and theoretical analyses reveal that the NDs weaken coordination of Li⁺ and solvents/anions, suppress graphite exfoliation, and promote a LiF/Li₂CO₃-rich SEI with low interfacial impedance, markedly enhancing the Li⁺ desolvation efficiency and diffusion kinetics at low temperatures. The graphite anodes based on ND-modified PC-electrolyte retain 96.7 % (360.1 mA h g⁻¹) and 67.2 % (250.4 mA h g⁻¹) of room-temperature theoretical capacity at −20 °C and −40 °C (0.2 C), surpassing conventional carbonate electrolyte by 44 %, and superior to most reported results. At 10 C (1C = 372 mA h g⁻¹), the system achieves 10000 cycles with 95 % capacity retention, driven by accelerated Li⁺ desolvation and enhanced SEI ion diffusion. This research offering a novel strategy for designing PC electrolytes that exhibit high performance, low-temperature compatibility, and robust stability.