v22.1

Features

• Half-cell models can now be run with "surface form" (#1913)
• Added option for different kinetics on anode and cathode (#1913)
• Allow pybamm.Solution.save_data() to return a string if filename is None, and added json to_format option (#1909)
• Added an option to force install compatible versions of jax and jaxlib if already installed using CLI (#1881)

Optimizations

• The Symbol nodes no longer subclasses anytree.NodeMixIn. This removes some checks that were not really needed (#1912)

Bug fixes

• Parameters can now be imported from any given path in Windows (#1900)
• Fixed initial conditions for the EC SEI model (#1895)
• Fixed issue in extraction of sensitivites (#1894)

v21.12

Features

• Added new kinetics models for asymmetric Butler-Volmer, linear kinetics, and Marcus-Hush-Chidsey (#1858)
• Experiments can be set to terminate when a voltage is reached (across all steps) (#1832)
• Added cylindrical geometry and finite volume method (#1824)

Bug fixes

• PyBaMM is now importable in Linux systems where jax is already installed (#1874)
• Simulations with drive cycles now support initial_soc (#1842)
• Fixed bug in expression tree simplification (#1831)
• Solid tortuosity is now correctly calculated with Bruggeman coefficient of the respective electrode (#1773)

v21.11

Features

• The name of a parameter set can be passed to ParameterValues as a string, e.g. ParameterValues("Chen2020") (#1822)
• Reformatted SEI growth models into a single submodel with conditionals (#1808)
• Stress-induced diffusion is now a separate model option instead of being automatically included when using the particle mechanics submodels (#1797)
• Experiments with drive cycles can be solved (#1793)
• Added surface area to volume ratio as a factor to the SEI equations (#1790)
• Half-cell SPM and SPMe have been implemented (#1731)

Bug fixes

• Fixed sympy operators for Arctan and Exponential (#1786)
• Fixed finite volume discretization in spherical polar coordinates (#1782)
• Fixed bug when using Experiment with a pouch cell model (#1707)
• Fixed bug when using Experiment with a plating model (#1707)
• Fixed hack for potentials in the SPMe model (#1707)

Breaking changes

• The chemistry keyword argument in ParameterValues has been deprecated. Use ParameterValues(chem) instead of ParameterValues(chemistry=chem) (#1822)
• Raise error when trying to convert an Interpolant with the "pchip" interpolator to CasADI (#1791)
• Raise error if Concatenation is used directly with Variable objects (concatenation should be used instead) (#1789)
• Made jax, jaxlib and the PyBaMM JaxSolver optional (#1767)

v21.10

Features

• Summary variables can now be user-determined (#1759)
• Added all_first_states to the Solution object for a simulation with experiment (#1759)
• Added a new method (create_gif) in QuickPlot, Simulation and BatchStudy to create a GIF of a simulation (#1754)
• Added more examples for the BatchStudy class (#1747)
• SEI models can now be included in the half-cell model (#1705)

Bug fixes

• Half-cell model and lead-acid models can now be simulated with Experiments (#1759)
• Removed in-place modification of the solution objects by QuickPlot (#1747)
• Fixed vector-vector multiplication bug that was causing errors in the SPM with constant voltage or power (#1735)

v21.9

Features

• Added thermal parameters (thermal conductivity, specific heat, etc.) to the Ecker2015 parameter set from Zhao et al. (2018) and Hales et al. (2019) (#1683)
• Added plot_summary_variables to plot and compare summary variables (#1678)
• The DFN model can now be used directly (instead of BasicDFNHalfCell) to simulate a half-cell (#1600)

Breaking changes

• Dropped support for Python 3.6 (#1696)
• The substring 'negative electrode' has been removed from variables related to SEI and lithium plating (e.g. 'Total negative electrode SEI thickness [m]' replaced by 'Total SEI thickness [m]') (#1654)

v21.08

This release introduces:

• the switch to calendar versioning: from now on we will use year.month version number
• sensitivity analysis of solutions with respect to input parameters
• several new models, including many-particle and state-of-health models
• improvement on how CasADI solver's handle events, including a new "fast with events" mode
• several other new features, optimizations, and bug fixes, summarized in CHANGELOG

v0.4.0

This release introduces:

• several new models, including reversible and irreversible plating submodels, submodels for loss of active material, Yang et al.'s (2017) coupled SEI/plating/pore clogging model, and the Newman-Tobias model
• internal optimizations for solving models, particularly for simulating experiments, with more accurate event detection and more efficient numerical methods and post-processing
• parallel solutions of a model with different inputs
• a cleaner installation process for Mac when installing from PyPI, no longer requiring a Homebrew installation of Sundials
• improved plotting functionality, including adding a new 'voltage component' plot
• several other new features, optimizations, and bug fixes, summarized in the CHANGELOG

v0.3.0

This release introduces a new aging model for particle swelling and cracking, a new reduced-order model (TSPMe), and a parameter set for A123 LFP cells. Additionally, there have been several backend optimizations to speed up model creation and solving, and other minor features and bug fixes. See CHANGELOG for more details.

v0.3.0-beta

This release introduces a new aging model for particle swelling and cracking, a new reduced-order model (TSPMe), and a parameter set for A123 LFP cells. Additionally, there have been several backend optimizations to speed up model creation and solving, and other minor features and bug fixes. See CHANGELOG for more details.

v0.2.4

This release adds new operators for more complex models, some basic sensitivity analysis, a half-cell DFN model, and a spectral volumes spatial method, as well as some small bug fixes. See CHANGELOG for more details.