ReliabilityLONGi's module, equipped with HPBC cell technology, demonstrated high resilience against extreme environmental stressors such as dust accumulation, heat and humidity, freezing conditions, strong UV exposure, and high corrosion. Zeng explained a few of the major reliability features of its HPBC modules.The Hi-MO X10 module, equipped with HPBC 2.0 cells and a soft breakdown design, prevents localized overheating caused by shading by allowing blocked current to bypass, ultimately mitigating the risk of hotspots. Zeng adds that this feature can reduce localized overheating in the HPBC cell-based module by more than 28% compared to the standard TOPCon cell-based module, while also mitigating the potential fire hazards of rooftop installations.Additionally, the HPBC module’s lower hotspot temperature – below 100°C – compared to the standard TOPCon module’s 170°C, ensures long-term durability. Regarding the UVID in HPBC 2.0 cells, the front-side passivation film, with up to 2% uniformity, exhibits effective resilience compared to the uneven front-side passivation layers of TOPCon cells caused by high-temperature boron diffusion. Corrosion of the module's metal contacts in hot and humid environments is primarily caused by a chemical reaction between acetic acid generated by the encapsulant and the lead (Pb) content in the metal electrode's alloy coating, as well as the aluminum content in the metallization paste, explained Zeng. However, the HPBC X10 module’s metal electrode, composed of 1/6th lead content compared to the TOPCon metallization ribbon, showed lower degradation under DH environments.LONGi's latest TaiRay wafer, featuring up to 16% higher maximum rupture strength and a thickness increase of up to 10 µm compared to mainstream wafers, demonstrates enhanced mechanical strength and reliability. Additionally, the full-back contact one-line welding process reduces cell edge stress to 26 MPa, compared to the higher edge stress of up to 50 MPa in TOPCon cells due to the Z-shaped metal contact soldering process. This ultimately improves the HPBC 2.0 module’s resistance to cell cracking.Cell technology roadmapStarting mass-scale production of HPBC 2.0 cells in Q4 2024, the company is poised to expand up to 10 GW by the end of next year. Furthermore, the HBC cell structure, BC cell based on HJT cell architecture, has achieved more than 27.3% lab-scale efficiency. This HBC cell, projected to come into mass production by Q1 2026, has the potential to reach 27%+ mass-scale efficiency in the future, says Zeng.
