Methods to achieve large-scale production of defect-free graphene are needed to enable the commercial development of graphene-based devices. It is now shown that high-shear mixing is an effective way to exfoliate graphene and other two-dimensional materials in liquid volumes up to hundreds of litres.

Printing nanosheet-network transistors: Two-dimensional (2D) materials such as graphene and metal chalcogenides such as tungsten diselenide (WSe2) are attractive for use in low-cost thin-film transistors (TFTs) because they have high charge-carrier mobility. Kelly et al. printed TFTs from networks of exfoliated dispersions of 2D materials with graphene contacts, WSe ₂ as the semiconductor, and a boron nitride separator. Electrolytic gating with ionic liquids enabled higher operating currents than achieved with comparable organic TFTs. Science , this issue p. 69

One weakness of batteries is the rapid falloff in charge-storage capacity with increasing charge/discharge rate. Rate performance is related to the timescales associated with charge/ionic motion in both electrode and electrolyte. However, no general fittable model exists to link capacity-rate data to electrode/electrolyte properties. Here we demonstrate an equation which can fit capacity versus rate data, outputting three parameters which fully describe rate performance. Most important is the characteristic time associated with charge/discharge which can be linked by a second equation to physical electrode/electrolyte parameters via various rate-limiting processes. We fit these equations to ~200 data sets, deriving parameters such as diffusion coefficients or electrolyte conductivities. It is possible to show which rate-limiting processes are dominant in a given situation, facilitating rational design and cell optimisation. In addition, this model predicts the upper speed limit for lithium/sodium ion batteries, yielding a value that is consistent with the fastest electrodes in the literature.