Bioinspired Cellulose-Based Ultra-Slippery Film with Superior Transmittance, Anti-Fouling and De-Icing Properties for the Durable and Efficient Output of Solar Panels.

High optical transmittance can endow solar panels with sufficient light energy intake, while anti-fouling and anti-icing properties ensure stable power generation in environments where dust, bird droppings, algae, and ice are prone to accumulate. A highly transparent and ultra-slippery surface is promising for meeting these requirements. However, it remains a huge challenge to achieve superior transmittance, anti-fouling, anti-icing, and durability on the same surface to ensure high energy conversion efficiency for solar panels. Herein, a bioinspired cellulose-based ultra-slippery film (BCUSF) with an extremely low water sliding angle (SA = 0.4°) and high transmittance (≈95% of bake glass) is reported. Benefiting from the impressive slippery property, remarkably low ice adhesion strength (0.38 kPa), and superior self-cleaning and anti-fouling performances are also demonstrated. Moreover, the BCUSF exhibits excellent durability and robustness, maintaining a SA of 0.8° after suffering high shear at 9000 r min^-1. Accordingly, the BCUSF with highly comprehensive performance enables solar panels to maintain high energy-conversion efficiency after repeated accumulation/cleaning of ice (ice adhesion strength = 0.91 kPa after 25 tests) and dust, or sand impact. It is envisioned that the BCUSF can boost the practical applications of slippery films on solar panels.