Biphenylite as Anode Materials for Alkali Metal Ion Batteries with Self-Enhanced Storage Mechanism

In this work, we theoretically investigate the feasibility
of biphenylite,
the van der Waals layered bulk structure from experimental biphenylene
network monolayers, as an anode material for alkali metal ions. The
results indicate that the theoretical properties of Li, Na, and K
in biphenylite are generally beyond those in graphite. Li–biphenylite
exhibits a high specific capacity of 744 mAh·g–1, with a corresponding voltage range of 0.90–0.36 V, low diffusion
barrier (<0.30 eV), and small volume change (∼9.9%), far
exceeding those of Li–graphite. Moreover, a novel self-enhanced
storage mechanism is observed and unveiled, in which the heavy intercalation
of Li atoms (i.e., electron doping) induces puckered distortion of
the nonhoneycomb carbon frameworks to enhance the intercalation ability
and capacity of Li ion via a chemical activation of carbon frameworks.
Possessing excellent anode performance beyond graphite, biphenylite
is a promising “all-around” anode material candidate
for alkali metal ion batteries, especially for lithium ion batteries.