Solar energy is the most important renewable energy, and its large-scale application is of great significance to achieve carbon neutrality. Photovoltaic (PV) power generation is one of the most important ways of solar energy utilisation. However, it faces two important bottlenecks. Current PV efficiency is far below the Landsberg limit, and more importantly, the intermittent nature of solar energy poses a huge challenge to large-scale energy storage technology, leading to the large-scale discarding of solar power around the world. To handle the issues, a concentrated spectral-splitting photovoltaic-thermal system is integrated with advanced technologies of PV cells and CO2 battery to maximise the uninterrupted utilisation of solar energy, especially optimising the system to achieve full-spectrum utilisation based on the solar spectrum properties. The results show that the round-trip efficiency can achieve higher than 88 %, the power produced by the turbine in discharging phase is higher than the input PV power in the charging phase when the bandgap energy (Eg) is higher than 1.2 eV, and the gap increases evidently as Eg rises. In the extreme case, >68 % of solar utilisation efficiency can be achieved. In the proposed system, CO2 is employed to reduce carbon emissions by harnessing its unique properties rather than simply capturing and burying it as a greenhouse gas, which not only provides a good solution for the intermittent nature of solar photovoltaic power but also obtains higher electrical power in discharging phase than the input photovoltaic power in charging phase, and it is easily scaled up, demonstrating the significant potential of the proposed concept in practical applications.