Abstract Seeking advanced and safer lithium-ion battery with sustainable characteristic is significant for the development of electronic devices and electric vehicles. Herein, a new porous TiO2 nanobundles (PTNBs) is synthesized though a scalable and green hydrothermal strategy from the TiO2 powders without using any high-cost and harmful organic titanium-based compounds. The PTNBs exhibits an extremely high lithium storage capacity of 296 mAh g−1 at 100 mA g−1, where the capacity can maintain over 146 mAh g−1 even after 500 cycles at 1000 mA g−1. To pursue more reliable Li-ion batteries, full batteries of PTNBs/LiNixMn1-xO4 (x = 0, 0.5) using spinel structured cathode are constructed. The batteries have the features of sustainability and deliver high capacities of 112 mAh gcathode−1 and 102 mAh gcathode−1 with stable capacity retentions of 99% and 90% over 140 cycles. Note that the energy densities can achieve as high as 267 and 270 Wh kgcathode−1 (535 and 540 Wh kganode−1) respectively, which is feasible to satisfy diverse requirements for energy storage products. We believe that the universal synthetic strategy, appealing structure and intriguing properties of PTNBs is applicable for wider applications, while the concept of sustainable strategy seeking reliable and safer Li-ion battery can attract broad interest.