A team from Zhejiang A&F University, Huazhong University of Science and Technology (HUST), and Stanford University have developed a binder-free, flexible, and free-standing electrode comprising an unprecedented 92% silicon content for Li-ion batteries.
The structure shows an ultrahigh electrode-specific capacity of 2700 mAh g−1, excellent cycling stability under a high silicon content of 85% (>2000 mAh g−1 after 300 cycles) and a commercial-level areal capacity (5.58 mAh cm−2). A paper on the work is published in the RSC journal Energy & Environmental Science.
The development of lithium-ion batteries (LIBs) with a reduced weight, higher capacity, and longer service life is considered to be the most important strategy to address the critical needs of applications such as next-generation mobile electronics and electric vehicles. Silicon (Si) has received wide-spread attention as the most promising anode material for the next generation of LIBs because of its high theoretical specific capacity of 3579 mAh g−1 (Li15Si4).
However, challenges arise owing to the large change in volume (>300%) under operation and poor electrical conductivity of Si, which significantly restricts the stability and kinetics process of the electrodes. In fact, to maintain electrode integrity, the industry has had to use a relatively low amount of Si (